{"api_version":"1","generated_at":"2026-08-21T02:38:28+00:00","cve":"CVE-2026-72466","urls":{"html":"https://cve.report/CVE-2026-72466","api":"https://cve.report/api/cve/CVE-2026-72466.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72466","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72466"},"summary":{"title":"xprtrdma: Fix bcall rep leak and unbounded peek","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Fix bcall rep leak and unbounded peek\n\nrpcrdma_is_bcall() decodes a reply's first words to decide whether\nthe frame is a backchannel call. Two issues in that decode path\nlet a short or malformed reply leak the receive buffer and drain\nthe Receive queue.\n\nFirst, the speculative peek\n\n    p = xdr_inline_decode(xdr, 0);\n    /* five p++ reads follow */\n\nasks xdr_inline_decode() for zero bytes, which returns xdr->p\nwithout consulting xdr->end. The five subsequent __be32 reads can\nthen walk up to 20 bytes past the wire payload into stale regbuf\ncontents and misclassify the reply as a backchannel call.\n\nSecond, after the post-peek\n\n    p = xdr_inline_decode(xdr, 3 * sizeof(*p));\n    if (unlikely(!p))\n            return true;\n\nthe short-header arm returns true without calling\nrpcrdma_bc_receive_call(). The contract with the caller is that a\ntrue return transfers ownership of rep to the backchannel path:\n\n    rpcrdma_reply_handler()\n      if (rpcrdma_is_bcall(r_xprt, rep))\n              return;        /* bare return, skips out_post */\n      ...\n    out_post:\n      rpcrdma_post_recvs(r_xprt, credits + ...);\n\nBecause rpcrdma_bc_receive_call() never ran, no one took rep, but\nrpcrdma_reply_handler still bare-returns past rpcrdma_rep_put()\nand rpcrdma_post_recvs(). The rep, with its persistently\nDMA-mapped receive buffer, is orphaned on rb_all_reps and freed\nonly at transport teardown. This completion reposts nothing, so\nits slot is reclaimed only when a later forward-channel reply\nreaches out_post and rpcrdma_post_recvs() allocates a fresh rep to\nbackfill; absent that traffic the Receive queue drains and the\npeer's Sends draw RNR NAKs.\n\nFix by consulting xdr->end after the zero-length peek so the five\n__be32 reads cannot run unless 20 bytes of wire payload remain. A\nbyte-precise comparison against xdr->end is required because a\nnon-4-aligned receive rounds the stream's word count up past the\ntrue payload. Also return false from the short-header arm so the\nreply falls through the normal out_norqst cleanup chain\n(rpcrdma_rep_put() plus rpcrdma_post_recvs()).","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:20","updated_at":"2026-08-17 06:19:14"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/d7a2870dde3bb09d51d6b9c877642996ad6b92dd","name":"https://git.kernel.org/stable/c/d7a2870dde3bb09d51d6b9c877642996ad6b92dd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0cee8f9c3b14bd6dee9c4310090a7f45b89b834f","name":"https://git.kernel.org/stable/c/0cee8f9c3b14bd6dee9c4310090a7f45b89b834f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/118a16a18c59f7ad8084b2d13988839b669fca10","name":"https://git.kernel.org/stable/c/118a16a18c59f7ad8084b2d13988839b669fca10","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/07aa506436be7634e381e1e1f6d0efa9efc81ecc","name":"https://git.kernel.org/stable/c/07aa506436be7634e381e1e1f6d0efa9efc81ecc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6","name":"https://git.kernel.org/stable/c/c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/88b5346284a184a6b7d019912232a571d672d3e3","name":"https://git.kernel.org/stable/c/88b5346284a184a6b7d019912232a571d672d3e3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7afc2f8d2fd9394724df9eaf22ce7a71029a5fba","name":"https://git.kernel.org/stable/c/7afc2f8d2fd9394724df9eaf22ce7a71029a5fba","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72466","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72466","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 0cee8f9c3b14bd6dee9c4310090a7f45b89b834f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 7afc2f8d2fd9394724df9eaf22ce7a71029a5fba git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 88b5346284a184a6b7d019912232a571d672d3e3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 07aa506436be7634e381e1e1f6d0efa9efc81ecc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 d7a2870dde3bb09d51d6b9c877642996ad6b92dd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 118a16a18c59f7ad8084b2d13988839b669fca10 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 41c8f70f5a3db7e06179186b6525fd9ee1d7d314 c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72466","cve":"CVE-2026-72466","epss":"0.007280000","percentile":"0.511540000","score_date":"2026-08-17","updated_at":"2026-08-18 00:11:47"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/sunrpc/xprtrdma/rpc_rdma.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"0cee8f9c3b14bd6dee9c4310090a7f45b89b834f","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"7afc2f8d2fd9394724df9eaf22ce7a71029a5fba","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"88b5346284a184a6b7d019912232a571d672d3e3","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"07aa506436be7634e381e1e1f6d0efa9efc81ecc","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"d7a2870dde3bb09d51d6b9c877642996ad6b92dd","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"118a16a18c59f7ad8084b2d13988839b669fca10","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"},{"lessThan":"c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6","status":"affected","version":"41c8f70f5a3db7e06179186b6525fd9ee1d7d314","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/sunrpc/xprtrdma/rpc_rdma.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.14"},{"lessThan":"4.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"4.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Fix bcall rep leak and unbounded peek\n\nrpcrdma_is_bcall() decodes a reply's first words to decide whether\nthe frame is a backchannel call. Two issues in that decode path\nlet a short or malformed reply leak the receive buffer and drain\nthe Receive queue.\n\nFirst, the speculative peek\n\n    p = xdr_inline_decode(xdr, 0);\n    /* five p++ reads follow */\n\nasks xdr_inline_decode() for zero bytes, which returns xdr->p\nwithout consulting xdr->end. The five subsequent __be32 reads can\nthen walk up to 20 bytes past the wire payload into stale regbuf\ncontents and misclassify the reply as a backchannel call.\n\nSecond, after the post-peek\n\n    p = xdr_inline_decode(xdr, 3 * sizeof(*p));\n    if (unlikely(!p))\n            return true;\n\nthe short-header arm returns true without calling\nrpcrdma_bc_receive_call(). The contract with the caller is that a\ntrue return transfers ownership of rep to the backchannel path:\n\n    rpcrdma_reply_handler()\n      if (rpcrdma_is_bcall(r_xprt, rep))\n              return;        /* bare return, skips out_post */\n      ...\n    out_post:\n      rpcrdma_post_recvs(r_xprt, credits + ...);\n\nBecause rpcrdma_bc_receive_call() never ran, no one took rep, but\nrpcrdma_reply_handler still bare-returns past rpcrdma_rep_put()\nand rpcrdma_post_recvs(). The rep, with its persistently\nDMA-mapped receive buffer, is orphaned on rb_all_reps and freed\nonly at transport teardown. This completion reposts nothing, so\nits slot is reclaimed only when a later forward-channel reply\nreaches out_post and rpcrdma_post_recvs() allocates a fresh rep to\nbackfill; absent that traffic the Receive queue drains and the\npeer's Sends draw RNR NAKs.\n\nFix by consulting xdr->end after the zero-length peek so the five\n__be32 reads cannot run unless 20 bytes of wire payload remain. A\nbyte-precise comparison against xdr->end is required because a\nnon-4-aligned receive rounds the stream's word count up past the\ntrue payload. Also return false from the short-header arm so the\nreply falls through the normal out_norqst cleanup chain\n(rpcrdma_rep_put() plus rpcrdma_post_recvs())."}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - The bug is reached when a remote RDMA peer's inbound message completes in rpcrdma_wc_receive() and rpcrdma_reply_handler() decodes it; a malicious or compromised NFS-over-RDMA server can send crafted short rdma_msg replies over the established RPC/RDMA connection without local access.\nAC:L - On an active NFSv4.1+ RPC/RDMA session the attacker fully controls inbound replies and can repeatedly send short/malformed rdma_msg frames to hit the zero-length peek and short-header return-true paths, reliably leaking receive buffers and draining the Receive queue.\nPR:N - Exploitation requires only network reachability as the connected RDMA/RPC peer (e.g., a malicious NFS server); no local account, mount privileges, or namespaced capabilities on the victim NFS client are needed to deliver the malformed RDMA replies.\nUI:N - Once an NFS-over-RDMA mount and NFSv4.1 backchannel session exist, triggering the flaw needs no additional victim action beyond the attacker sending malicious RDMA receive payloads during normal client-server communication.\nS:U - The vulnerability and its impact remain within the NFS client's kernel SUNRPC/xprtrdma transport context; it does not cross a VM, container, or IOMMU security boundary to affect other authorities.\nC:H - xdr_inline_decode(xdr,0) permits up to five subsequent __be32 reads past the wire payload into stale receive-buffer contents, an out-of-bounds read that can misclassify replies and expose remnants of prior RPC/NFS data to unintended processing paths.\nI:H - Stale-buffer-assisted misclassification can treat a forward-channel reply as a backchannel RPC_CALL, a type confusion that routes attacker-influenced bytes into rpcrdma_bc_receive_call()/NFSv4 callback handling and can corrupt client session state.\nA:H - Each successful trigger orphans a DMA-mapped rpcrdma_rep and skips rpcrdma_post_recvs(), monotonically draining the RDMA Receive queue until the peer gets RNR NAKs and the NFS-over-RDMA connection becomes unusable, enabling sustained remote denial of service."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:44:32.887Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/0cee8f9c3b14bd6dee9c4310090a7f45b89b834f"},{"url":"https://git.kernel.org/stable/c/7afc2f8d2fd9394724df9eaf22ce7a71029a5fba"},{"url":"https://git.kernel.org/stable/c/88b5346284a184a6b7d019912232a571d672d3e3"},{"url":"https://git.kernel.org/stable/c/07aa506436be7634e381e1e1f6d0efa9efc81ecc"},{"url":"https://git.kernel.org/stable/c/d7a2870dde3bb09d51d6b9c877642996ad6b92dd"},{"url":"https://git.kernel.org/stable/c/118a16a18c59f7ad8084b2d13988839b669fca10"},{"url":"https://git.kernel.org/stable/c/c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6"}],"title":"xprtrdma: Fix bcall rep leak and unbounded peek","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72466","datePublished":"2026-08-15T05:57:09.847Z","dateReserved":"2026-08-09T03:40:39.933Z","dateUpdated":"2026-08-17T05:44:32.887Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:20","lastModifiedDate":"2026-08-17 06:19:14","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72466","Ordinal":"1","Title":"xprtrdma: Fix bcall rep leak and unbounded peek","CVE":"CVE-2026-72466","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72466","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Fix bcall rep leak and unbounded peek\n\nrpcrdma_is_bcall() decodes a reply's first words to decide whether\nthe frame is a backchannel call. Two issues in that decode path\nlet a short or malformed reply leak the receive buffer and drain\nthe Receive queue.\n\nFirst, the speculative peek\n\n    p = xdr_inline_decode(xdr, 0);\n    /* five p++ reads follow */\n\nasks xdr_inline_decode() for zero bytes, which returns xdr->p\nwithout consulting xdr->end. The five subsequent __be32 reads can\nthen walk up to 20 bytes past the wire payload into stale regbuf\ncontents and misclassify the reply as a backchannel call.\n\nSecond, after the post-peek\n\n    p = xdr_inline_decode(xdr, 3 * sizeof(*p));\n    if (unlikely(!p))\n            return true;\n\nthe short-header arm returns true without calling\nrpcrdma_bc_receive_call(). The contract with the caller is that a\ntrue return transfers ownership of rep to the backchannel path:\n\n    rpcrdma_reply_handler()\n      if (rpcrdma_is_bcall(r_xprt, rep))\n              return;        /* bare return, skips out_post */\n      ...\n    out_post:\n      rpcrdma_post_recvs(r_xprt, credits + ...);\n\nBecause rpcrdma_bc_receive_call() never ran, no one took rep, but\nrpcrdma_reply_handler still bare-returns past rpcrdma_rep_put()\nand rpcrdma_post_recvs(). The rep, with its persistently\nDMA-mapped receive buffer, is orphaned on rb_all_reps and freed\nonly at transport teardown. This completion reposts nothing, so\nits slot is reclaimed only when a later forward-channel reply\nreaches out_post and rpcrdma_post_recvs() allocates a fresh rep to\nbackfill; absent that traffic the Receive queue drains and the\npeer's Sends draw RNR NAKs.\n\nFix by consulting xdr->end after the zero-length peek so the five\n__be32 reads cannot run unless 20 bytes of wire payload remain. A\nbyte-precise comparison against xdr->end is required because a\nnon-4-aligned receive rounds the stream's word count up past the\ntrue payload. Also return false from the short-header arm so the\nreply falls through the normal out_norqst cleanup chain\n(rpcrdma_rep_put() plus rpcrdma_post_recvs()).","Type":"Description","Title":"xprtrdma: Fix bcall rep leak and unbounded peek"}]}}}