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GHSA-W5HJ-MMMX-P42J

Vulnerability from github – Published: 2026-09-16 09:30 – Updated: 2026-09-16 15:30
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full

The depth check in xfrm6_input_addr() is off by one:

if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ... sp->xvec[sp->len++] = x;

xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode receive path re-enters IPv6 input via xfrm_trans_reinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6_input_addr() is called with sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS flags it and panics under panic_on_warn.

Use "sp->len >= XFRM_MAX_DEPTH", matching xfrm_input(). This also restores one chain level the old check rejected at sp->len == 5.

UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10 index 6 is out of range for type 'xfrm_state *[6]'

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-89783"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T09:17:08Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full\n\nThe depth check in xfrm6_input_addr() is off by one:\n\n  if (1 + sp-\u003elen == XFRM_MAX_DEPTH)\n          goto drop;\n  ...\n  sp-\u003exvec[sp-\u003elen++] = x;\n\nxfrm_input() can leave sp-\u003elen == XFRM_MAX_DEPTH, and the transport-mode\nreceive path re-enters IPv6 input via xfrm_trans_reinject() with that\nsecpath preserved. If the inner packet carries a destination-options HAO\noption or a type-2 routing header, xfrm6_input_addr() is called with\nsp-\u003elen == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so\nsp-\u003exvec[sp-\u003elen++] writes one slot past the 6-element xvec[]. The write\nstays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS\nflags it and panics under panic_on_warn.\n\nUse \"sp-\u003elen \u003e= XFRM_MAX_DEPTH\", matching xfrm_input(). This also\nrestores one chain level the old check rejected at sp-\u003elen == 5.\n\n  UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10\n  index 6 is out of range for type \u0027xfrm_state *[6]\u0027",
  "id": "GHSA-w5hj-mmmx-p42j",
  "modified": "2026-09-16T15:30:57Z",
  "published": "2026-09-16T09:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89783"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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