SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry

{
  "id": "4d1887b71888ebb4c3c816f9c8cfc34d9e8acc4aeaa3503745f07425db6f3bf6",
  "url": "https://osv.dev/vulnerability/CVE-2026-93207",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry svcauth_gss_decode_credbody() writes the caller's rpc_gss_wire_cred field by field and assigns gc_ctx.len only on the success tail. The caller storage is svcdata->clcred, which lives in the per-svc_rqst gss_svc_data and is reused across requests. Early decode failures leave partially decoded state mixed with residue from the prior request. The trailing body_len tightness check is the sharpest case: xdr_stream_decode_opaque_inline() has already written gc_ctx.data with a borrowed inline pointer into the current request's XDR pages, but gc_ctx.len retains its prior value. Once the request pages are released the pooled clcred carries a dangling pointer paired with a stale length. Zero the caller's rpc_gss_wire_cred at function entry so that every early-return path leaves a deterministic all-zero cred. On the trailing tightness-check path, gc_ctx.len is now zero instead of stale, which neuters length-driven consumers such as gss_svc_searchbyctx() that would otherwise walk the dangling data pointer.",
    "evidence": "osv:CVE-2026-93207",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.109",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-93207",
      "aliases": [
        "CVE-2026-93207"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "b0bc53470d1af01f62a0fe2d405cf56477804863"
                },
                {
                  "fixed": "56b29d62017c7dd1718d060dd5b3a2ce61095d0c"
                },
                {
                  "fixed": "0e18641708eaa8bc3c1ff338cd844aeadbd52bac"
                },
                {
                  "fixed": "e0778464049b0238f2915a40007a4154f86cf351"
                },
                {
                  "fixed": "0fa8a8acae57e6373962741d5b06d13f44aba6a9"
                },
                {
                  "fixed": "11539e8fcce0b0af062ae5fecf7b3676c2f7aeed"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93207.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.3.0"
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                {
                  "fixed": "6.6.157"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.109"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.50"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93207.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.108027936Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0e18641708eaa8bc3c1ff338cd844aeadbd52bac",
        "https://git.kernel.org/stable/c/0fa8a8acae57e6373962741d5b06d13f44aba6a9",
        "https://git.kernel.org/stable/c/11539e8fcce0b0af062ae5fecf7b3676c2f7aeed",
        "https://git.kernel.org/stable/c/56b29d62017c7dd1718d060dd5b3a2ce61095d0c",
        "https://git.kernel.org/stable/c/e0778464049b0238f2915a40007a4154f86cf351",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93207.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-93207",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93207.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-93207",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 487395,
  "published_at": "2026-09-24T15:10:30.942+00:00"
}