{"api_version":"1","generated_at":"2026-09-12T11:37:26+00:00","cve":"CVE-2026-89541","urls":{"html":"https://cve.report/CVE-2026-89541","api":"https://cve.report/api/cve/CVE-2026-89541.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89541","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89541"},"summary":{"title":"SUNRPC: harden gss_unwrap_resp_priv length checks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: harden gss_unwrap_resp_priv length checks\n\ngss_unwrap_resp_priv() validates the RPCSEC_GSS opaque length with\n\n    offset = (u8 *)(p) - (u8 *)head->iov_base;\n    if (offset + opaque_len > rcv_buf->len)\n            goto unwrap_failed;\n    maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset,\n                          offset + opaque_len, rcv_buf);\n\nBoth operands are u32 and the sum is computed in u32. A reply with\nopaque_len near 0xffffffff makes offset + opaque_len wrap to a small\nvalue that is below rcv_buf->len, so the bound check passes and\ngss_unwrap() is called with end < begin. The check also lacks a\nlower bound, so any opaque_len in [0, GSS_KRB5_TOK_HDR_LEN) is\naccepted and forwarded to gss_krb5_unwrap_v2(), whose pre-decrypt\nheader reads at ptr+4 and ptr+6 then run past the token.\n\nA krb5p NFS server returning a crafted RPCSEC_GSS reply can drive\nthe client into out-of-bounds reads in gss_krb5_unwrap_v2() and the\nrotate_left() loop that follows.\n\nFix by replacing the single combined check with three guards that\nare safe in u32 arithmetic and that enforce the RFC 4121 minimum\nouter token length:\n\n    if (offset > rcv_buf->len)\n            goto unwrap_failed;\n    if (opaque_len > rcv_buf->len - offset)\n            goto unwrap_failed;\n    if (opaque_len < GSS_KRB5_TOK_HDR_LEN)\n            goto unwrap_failed;\n\nThe first guard makes the subtraction in the second guard\nunconditionally safe; offset is derived from a successful\nxdr_inline_decode() in the head kvec, so in practice it already\nsatisfies the bound. The floor mirrors the server-side check added\nin commit 5b757c2e57a5 (\"SUNRPC: svcauth_gss: enforce krb5 token\nminimum length\").","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:37","updated_at":"2026-09-11 20:19:37"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/87831b92112c81db251d46756d65daa4f91af6a2","name":"https://git.kernel.org/stable/c/87831b92112c81db251d46756d65daa4f91af6a2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/89a15a50f84d32d4b99db86f957427fcbe20a99a","name":"https://git.kernel.org/stable/c/89a15a50f84d32d4b99db86f957427fcbe20a99a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ebcbd2523a8524c3d24e111cdbed8e271d910269","name":"https://git.kernel.org/stable/c/ebcbd2523a8524c3d24e111cdbed8e271d910269","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d395c30d570ca6168f0297b191709927d1258273","name":"https://git.kernel.org/stable/c/d395c30d570ca6168f0297b191709927d1258273","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89541","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89541","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d2da60c63b67174add32f06e8d54c3a0c5cd9cf 89a15a50f84d32d4b99db86f957427fcbe20a99a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d2da60c63b67174add32f06e8d54c3a0c5cd9cf ebcbd2523a8524c3d24e111cdbed8e271d910269 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d2da60c63b67174add32f06e8d54c3a0c5cd9cf d395c30d570ca6168f0297b191709927d1258273 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d2da60c63b67174add32f06e8d54c3a0c5cd9cf 87831b92112c81db251d46756d65daa4f91af6a2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/sunrpc/auth_gss/auth_gss.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"89a15a50f84d32d4b99db86f957427fcbe20a99a","status":"affected","version":"2d2da60c63b67174add32f06e8d54c3a0c5cd9cf","versionType":"git"},{"lessThan":"ebcbd2523a8524c3d24e111cdbed8e271d910269","status":"affected","version":"2d2da60c63b67174add32f06e8d54c3a0c5cd9cf","versionType":"git"},{"lessThan":"d395c30d570ca6168f0297b191709927d1258273","status":"affected","version":"2d2da60c63b67174add32f06e8d54c3a0c5cd9cf","versionType":"git"},{"lessThan":"87831b92112c81db251d46756d65daa4f91af6a2","status":"affected","version":"2d2da60c63b67174add32f06e8d54c3a0c5cd9cf","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/sunrpc/auth_gss/auth_gss.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.15"},{"lessThan":"2.6.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"2.6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"2.6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"2.6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"2.6.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: harden gss_unwrap_resp_priv length checks\n\ngss_unwrap_resp_priv() validates the RPCSEC_GSS opaque length with\n\n    offset = (u8 *)(p) - (u8 *)head->iov_base;\n    if (offset + opaque_len > rcv_buf->len)\n            goto unwrap_failed;\n    maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset,\n                          offset + opaque_len, rcv_buf);\n\nBoth operands are u32 and the sum is computed in u32. A reply with\nopaque_len near 0xffffffff makes offset + opaque_len wrap to a small\nvalue that is below rcv_buf->len, so the bound check passes and\ngss_unwrap() is called with end < begin. The check also lacks a\nlower bound, so any opaque_len in [0, GSS_KRB5_TOK_HDR_LEN) is\naccepted and forwarded to gss_krb5_unwrap_v2(), whose pre-decrypt\nheader reads at ptr+4 and ptr+6 then run past the token.\n\nA krb5p NFS server returning a crafted RPCSEC_GSS reply can drive\nthe client into out-of-bounds reads in gss_krb5_unwrap_v2() and the\nrotate_left() loop that follows.\n\nFix by replacing the single combined check with three guards that\nare safe in u32 arithmetic and that enforce the RFC 4121 minimum\nouter token length:\n\n    if (offset > rcv_buf->len)\n            goto unwrap_failed;\n    if (opaque_len > rcv_buf->len - offset)\n            goto unwrap_failed;\n    if (opaque_len < GSS_KRB5_TOK_HDR_LEN)\n            goto unwrap_failed;\n\nThe first guard makes the subtraction in the second guard\nunconditionally safe; offset is derived from a successful\nxdr_inline_decode() in the head kvec, so in practice it already\nsatisfies the bound. The floor mirrors the server-side check added\nin commit 5b757c2e57a5 (\"SUNRPC: svcauth_gss: enforce krb5 token\nminimum length\")."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:44:18.188Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/89a15a50f84d32d4b99db86f957427fcbe20a99a"},{"url":"https://git.kernel.org/stable/c/ebcbd2523a8524c3d24e111cdbed8e271d910269"},{"url":"https://git.kernel.org/stable/c/d395c30d570ca6168f0297b191709927d1258273"},{"url":"https://git.kernel.org/stable/c/87831b92112c81db251d46756d65daa4f91af6a2"}],"title":"SUNRPC: harden gss_unwrap_resp_priv length checks","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89541","datePublished":"2026-09-11T19:44:18.188Z","dateReserved":"2026-09-11T19:38:34.721Z","dateUpdated":"2026-09-11T19:44:18.188Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:37","lastModifiedDate":"2026-09-11 20:19:37","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89541","Ordinal":"1","Title":"SUNRPC: harden gss_unwrap_resp_priv length checks","CVE":"CVE-2026-89541","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89541","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: harden gss_unwrap_resp_priv length checks\n\ngss_unwrap_resp_priv() validates the RPCSEC_GSS opaque length with\n\n    offset = (u8 *)(p) - (u8 *)head->iov_base;\n    if (offset + opaque_len > rcv_buf->len)\n            goto unwrap_failed;\n    maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset,\n                          offset + opaque_len, rcv_buf);\n\nBoth operands are u32 and the sum is computed in u32. A reply with\nopaque_len near 0xffffffff makes offset + opaque_len wrap to a small\nvalue that is below rcv_buf->len, so the bound check passes and\ngss_unwrap() is called with end < begin. The check also lacks a\nlower bound, so any opaque_len in [0, GSS_KRB5_TOK_HDR_LEN) is\naccepted and forwarded to gss_krb5_unwrap_v2(), whose pre-decrypt\nheader reads at ptr+4 and ptr+6 then run past the token.\n\nA krb5p NFS server returning a crafted RPCSEC_GSS reply can drive\nthe client into out-of-bounds reads in gss_krb5_unwrap_v2() and the\nrotate_left() loop that follows.\n\nFix by replacing the single combined check with three guards that\nare safe in u32 arithmetic and that enforce the RFC 4121 minimum\nouter token length:\n\n    if (offset > rcv_buf->len)\n            goto unwrap_failed;\n    if (opaque_len > rcv_buf->len - offset)\n            goto unwrap_failed;\n    if (opaque_len < GSS_KRB5_TOK_HDR_LEN)\n            goto unwrap_failed;\n\nThe first guard makes the subtraction in the second guard\nunconditionally safe; offset is derived from a successful\nxdr_inline_decode() in the head kvec, so in practice it already\nsatisfies the bound. The floor mirrors the server-side check added\nin commit 5b757c2e57a5 (\"SUNRPC: svcauth_gss: enforce krb5 token\nminimum length\").","Type":"Description","Title":"SUNRPC: harden gss_unwrap_resp_priv length checks"}]}}}