Vulnerability-Lookup

GHSA-JRVQ-M3V6-8WM9

Vulnerability from github – Published: 2026-05-01 15:30 – Updated: 2026-05-06 21:31

Details

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

rxrpc: Fix missing validation of ticket length in non-XDR key preparsing

In rxrpc_preparse(), there are two paths for parsing key payloads: the XDR path (for large payloads) and the non-XDR path (for payloads <= 28 bytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly validates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR path fails to do so.

This allows an unprivileged user to provide a very large ticket length. When this key is later read via rxrpc_read(), the total token size (toksize) calculation results in a value that exceeds AFSTOKEN_LENGTH_MAX, triggering a WARN_ON().

[ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc]

Fix this by adding a check in the non-XDR parsing path of rxrpc_preparse() to ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX, bringing it into parity with the XDR parsing logic.

Severity ?

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-31696"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-01T14:16:19Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix missing validation of ticket length in non-XDR key preparsing\n\nIn rxrpc_preparse(), there are two paths for parsing key payloads: the\nXDR path (for large payloads) and the non-XDR path (for payloads \u003c= 28\nbytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly\nvalidates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR\npath fails to do so.\n\nThis allows an unprivileged user to provide a very large ticket length.\nWhen this key is later read via rxrpc_read(), the total\ntoken size (toksize) calculation results in a value that exceeds\nAFSTOKEN_LENGTH_MAX, triggering a WARN_ON().\n\n[ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc]\n\nFix this by adding a check in the non-XDR parsing path of rxrpc_preparse()\nto ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX,\nbringing it into parity with the XDR parsing logic.",
  "id": "GHSA-jrvq-m3v6-8wm9",
  "modified": "2026-05-06T21:31:31Z",
  "published": "2026-05-01T15:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31696"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1fa36cf495b0023e8475d038535c05e4063211e1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4458757c020592a3094366e0fb20457383b42f92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a1be1c9ece26cea69654f28b255ff9a7906b897b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ac33733b10b484d666f97688561670afd5861383"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce383ba615339f8eaec646a166d2c2b015bb5ca0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-31696 (GCVE-0-2026-31696)

Vulnerability from cvelistv5 – Published: 2026-05-01 13:55 – Updated: 2026-05-01 13:55

Title

rxrpc: Fix missing validation of ticket length in non-XDR key preparsing

Summary

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix missing validation of ticket length in non-XDR key preparsing In rxrpc_preparse(), there are two paths for parsing key payloads: the XDR path (for large payloads) and the non-XDR path (for payloads <= 28 bytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly validates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR path fails to do so. This allows an unprivileged user to provide a very large ticket length. When this key is later read via rxrpc_read(), the total token size (toksize) calculation results in a value that exceeds AFSTOKEN_LENGTH_MAX, triggering a WARN_ON(). [ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc] Fix this by adding a check in the non-XDR parsing path of rxrpc_preparse() to ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX, bringing it into parity with the XDR parsing logic.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/1fa36cf495b0023e8…
	https://git.kernel.org/stable/c/4458757c020592a30…
	https://git.kernel.org/stable/c/ce383ba615339f8ea…
	https://git.kernel.org/stable/c/a1be1c9ece26cea69…
	https://git.kernel.org/stable/c/ac33733b10b484d66…

Impacted products

Vendor

Product

Version

Linux

Affected: 8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 , < 1fa36cf495b0023e8475d038535c05e4063211e1 (git)
Affected: 8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 , < 4458757c020592a3094366e0fb20457383b42f92 (git)
Affected: 8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 , < ce383ba615339f8eaec646a166d2c2b015bb5ca0 (git)
Affected: 8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 , < a1be1c9ece26cea69654f28b255ff9a7906b897b (git)
Affected: 8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247 , < ac33733b10b484d666f97688561670afd5861383 (git)

Linux

Affected: 3.17
Unaffected: 0 , < 3.17 (semver)
Unaffected: 6.6.136 , ≤ 6.6.* (semver)
Unaffected: 6.12.84 , ≤ 6.12.* (semver)
Unaffected: 6.18.25 , ≤ 6.18.* (semver)
Unaffected: 7.0.2 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/rxrpc/key.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1fa36cf495b0023e8475d038535c05e4063211e1",
              "status": "affected",
              "version": "8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247",
              "versionType": "git"
            },
            {
              "lessThan": "4458757c020592a3094366e0fb20457383b42f92",
              "status": "affected",
              "version": "8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247",
              "versionType": "git"
            },
            {
              "lessThan": "ce383ba615339f8eaec646a166d2c2b015bb5ca0",
              "status": "affected",
              "version": "8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247",
              "versionType": "git"
            },
            {
              "lessThan": "a1be1c9ece26cea69654f28b255ff9a7906b897b",
              "status": "affected",
              "version": "8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247",
              "versionType": "git"
            },
            {
              "lessThan": "ac33733b10b484d666f97688561670afd5861383",
              "status": "affected",
              "version": "8a7a3eb4ddbe7c7e639170a64adede7cbd5a9247",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/rxrpc/key.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.17"
            },
            {
              "lessThan": "3.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.136",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.84",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.25",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.136",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.84",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.25",
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                },
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                  "versionStartIncluding": "3.17",
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                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
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        {
          "lang": "en",
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        }
      ],
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/1fa36cf495b0023e8475d038535c05e4063211e1"
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        {
          "url": "https://git.kernel.org/stable/c/4458757c020592a3094366e0fb20457383b42f92"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce383ba615339f8eaec646a166d2c2b015bb5ca0"
        },
        {
          "url": "https://git.kernel.org/stable/c/a1be1c9ece26cea69654f28b255ff9a7906b897b"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac33733b10b484d666f97688561670afd5861383"
        }
      ],
      "title": "rxrpc: Fix missing validation of ticket length in non-XDR key preparsing",
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        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31696",
    "datePublished": "2026-05-01T13:55:57.485Z",
    "dateReserved": "2026-03-09T15:48:24.131Z",
    "dateUpdated": "2026-05-01T13:55:57.485Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

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GHSA-JRVQ-M3V6-8WM9

CVE-2026-31696 (GCVE-0-2026-31696)

Tags

Sightings

Nomenclature