{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "2d2da60c63b67174add32f06e8d54c3a0c5cd9cf"
            },
            {
              "fixed": "3691c4b3488d8ca046b9941e5be30c626dbbbb50"
            },
            {
              "fixed": "85fa6b12e8f439739ac36ef2aad925f37c8b976a"
            },
            {
              "fixed": "401f6a5b338d05bb1069ad814d9f77e3c367854f"
            },
            {
              "fixed": "81fd7654a8429718adfcb2a7e03496077f547ed0"
            },
            {
              "fixed": "89a15a50f84d32d4b99db86f957427fcbe20a99a"
            },
            {
              "fixed": "ebcbd2523a8524c3d24e111cdbed8e271d910269"
            },
            {
              "fixed": "d395c30d570ca6168f0297b191709927d1258273"
            },
            {
              "fixed": "87831b92112c81db251d46756d65daa4f91af6a2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.15"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.221"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.188"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89541.json"
  },
  "details": "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-\u003eiov_base;\n    if (offset + opaque_len \u003e rcv_buf-\u003elen)\n            goto unwrap_failed;\n    maj_stat = gss_unwrap(ctx-\u003egc_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-\u003elen, so the bound check passes and\ngss_unwrap() is called with end \u003c 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 \u003e rcv_buf-\u003elen)\n            goto unwrap_failed;\n    if (opaque_len \u003e rcv_buf-\u003elen - offset)\n            goto unwrap_failed;\n    if (opaque_len \u003c 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\").",
  "id": "CVE-2026-89541",
  "modified": "2026-09-15T03:30:43.202501279Z",
  "published": "2026-09-11T19:44:18.188Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3691c4b3488d8ca046b9941e5be30c626dbbbb50"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/401f6a5b338d05bb1069ad814d9f77e3c367854f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81fd7654a8429718adfcb2a7e03496077f547ed0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/85fa6b12e8f439739ac36ef2aad925f37c8b976a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/87831b92112c81db251d46756d65daa4f91af6a2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/89a15a50f84d32d4b99db86f957427fcbe20a99a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d395c30d570ca6168f0297b191709927d1258273"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ebcbd2523a8524c3d24e111cdbed8e271d910269"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89541.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89541"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SUNRPC: harden gss_unwrap_resp_priv length checks"
}