{"api_version":"1","generated_at":"2026-06-02T17:31:28+00:00","cve":"CVE-2026-45856","urls":{"html":"https://cve.report/CVE-2026-45856","api":"https://cve.report/api/cve/CVE-2026-45856.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-45856","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-45856"},"summary":{"title":"RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send\n\nib_uverbs_post_send() uses cmd.wqe_size from userspace without any\nvalidation before passing it to kmalloc() and using the allocated\nbuffer as struct ib_uverbs_send_wr.\n\nIf a user provides a small wqe_size value (e.g., 1), kmalloc() will\nsucceed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,\nand other fields will read beyond the allocated buffer, resulting in\nan out-of-bounds read from kernel heap memory. This could potentially\nleak sensitive kernel information to userspace.\n\nAdditionally, providing an excessively large wqe_size can trigger a\nWARNING in the memory allocation path, as reported by syzkaller.\n\nThis is inconsistent with ib_uverbs_unmarshall_recv() which properly\nvalidates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before\nproceeding.\n\nAdd the same validation for ib_uverbs_post_send() to ensure wqe_size\nis at least sizeof(struct ib_uverbs_send_wr).","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:16:57","updated_at":"2026-05-30 11:17:07"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/bf4454da8b1e712714628c0a0d6e7845bb40790a","name":"https://git.kernel.org/stable/c/bf4454da8b1e712714628c0a0d6e7845bb40790a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/01c9b152647dc70dc06a4a2eff86ebb3b3c76075","name":"https://git.kernel.org/stable/c/01c9b152647dc70dc06a4a2eff86ebb3b3c76075","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d533425ac1f2925b4fc3e4ed9b9d72362cb23475","name":"https://git.kernel.org/stable/c/d533425ac1f2925b4fc3e4ed9b9d72362cb23475","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9b5ac1c15334d46c0dbd49d64a2257b929500163","name":"https://git.kernel.org/stable/c/9b5ac1c15334d46c0dbd49d64a2257b929500163","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bf1feed1a7886af945f92890493aefd2b5c9928a","name":"https://git.kernel.org/stable/c/bf1feed1a7886af945f92890493aefd2b5c9928a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0","name":"https://git.kernel.org/stable/c/1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7","name":"https://git.kernel.org/stable/c/9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bef70ff9841990658610512b4a18e4a88c9b4df6","name":"https://git.kernel.org/stable/c/bef70ff9841990658610512b4a18e4a88c9b4df6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45856","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45856","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c3bea3d2dc5358e05541527283279102383b0231 9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c3bea3d2dc5358e05541527283279102383b0231 9b5ac1c15334d46c0dbd49d64a2257b929500163 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c3bea3d2dc5358e05541527283279102383b0231 01c9b152647dc70dc06a4a2eff86ebb3b3c76075 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c3bea3d2dc5358e05541527283279102383b0231 bf1feed1a7886af945f92890493aefd2b5c9928a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.202 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.165 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.128 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.75 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.14 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.4 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"45856","cve":"CVE-2026-45856","epss":"0.000120000","percentile":"0.018360000","score_date":"2026-06-01","updated_at":"2026-06-02 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the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send\n\nib_uverbs_post_send() uses cmd.wqe_size from userspace without any\nvalidation before passing it to kmalloc() and using the allocated\nbuffer as struct ib_uverbs_send_wr.\n\nIf a user provides a small wqe_size value (e.g., 1), kmalloc() will\nsucceed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,\nand other fields will read beyond the allocated buffer, resulting in\nan out-of-bounds read from kernel heap memory. This could potentially\nleak sensitive kernel information to userspace.\n\nAdditionally, providing an excessively large wqe_size can trigger a\nWARNING in the memory allocation path, as reported by syzkaller.\n\nThis is inconsistent with ib_uverbs_unmarshall_recv() which properly\nvalidates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before\nproceeding.\n\nAdd the same validation for ib_uverbs_post_send() to ensure wqe_size\nis at least sizeof(struct ib_uverbs_send_wr)."}],"metrics":[{"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-05-30T10:45:33.505Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7"},{"url":"https://git.kernel.org/stable/c/9b5ac1c15334d46c0dbd49d64a2257b929500163"},{"url":"https://git.kernel.org/stable/c/01c9b152647dc70dc06a4a2eff86ebb3b3c76075"},{"url":"https://git.kernel.org/stable/c/bf1feed1a7886af945f92890493aefd2b5c9928a"},{"url":"https://git.kernel.org/stable/c/d533425ac1f2925b4fc3e4ed9b9d72362cb23475"},{"url":"https://git.kernel.org/stable/c/bf4454da8b1e712714628c0a0d6e7845bb40790a"},{"url":"https://git.kernel.org/stable/c/bef70ff9841990658610512b4a18e4a88c9b4df6"},{"url":"https://git.kernel.org/stable/c/1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0"}],"title":"RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-45856","datePublished":"2026-05-27T12:15:33.209Z","dateReserved":"2026-05-13T15:03:33.079Z","dateUpdated":"2026-05-30T10:45:33.505Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:16:57","lastModifiedDate":"2026-05-30 11:17:07","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"45856","Ordinal":"1","Title":"RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post","CVE":"CVE-2026-45856","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"45856","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send\n\nib_uverbs_post_send() uses cmd.wqe_size from userspace without any\nvalidation before passing it to kmalloc() and using the allocated\nbuffer as struct ib_uverbs_send_wr.\n\nIf a user provides a small wqe_size value (e.g., 1), kmalloc() will\nsucceed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,\nand other fields will read beyond the allocated buffer, resulting in\nan out-of-bounds read from kernel heap memory. This could potentially\nleak sensitive kernel information to userspace.\n\nAdditionally, providing an excessively large wqe_size can trigger a\nWARNING in the memory allocation path, as reported by syzkaller.\n\nThis is inconsistent with ib_uverbs_unmarshall_recv() which properly\nvalidates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before\nproceeding.\n\nAdd the same validation for ib_uverbs_post_send() to ensure wqe_size\nis at least sizeof(struct ib_uverbs_send_wr).","Type":"Description","Title":"RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post"}]}}}