Vulnerability-Lookup

FKIE_CVE-2026-31640

Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-04-24 17:51

Severity ?

Summary

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial In rxrpc_post_response(), the code should be comparing the challenge serial number from the cached response before deciding to switch to a newer response, but looks at the newer packet private data instead, rendering the comparison always false. Fix this by switching to look at the older packet. Fix further[1] to substitute the new packet in place of the old one if newer and also to release whichever we don't use.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/20386e7f8d97475b8d815873e246423317ec4260
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9132b1a7bf83b4a8042fffbc99d075b727a16742
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b33f5741bb187db8ff32e8f5b96def77cc94dfca

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix use of wrong skb when comparing queued RESP challenge serial\n\nIn rxrpc_post_response(), the code should be comparing the challenge serial\nnumber from the cached response before deciding to switch to a newer\nresponse, but looks at the newer packet private data instead, rendering the\ncomparison always false.\n\nFix this by switching to look at the older packet.\n\nFix further[1] to substitute the new packet in place of the old one if\nnewer and also to release whichever we don\u0027t use."
    }
  ],
  "id": "CVE-2026-31640",
  "lastModified": "2026-04-24T17:51:40.810",
  "metrics": {},
  "published": "2026-04-24T15:16:43.357",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/20386e7f8d97475b8d815873e246423317ec4260"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9132b1a7bf83b4a8042fffbc99d075b727a16742"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b33f5741bb187db8ff32e8f5b96def77cc94dfca"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

CVE-2026-31640 (GCVE-0-2026-31640)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:44 – Updated: 2026-04-24 14:44

Title

rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial

Summary

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/9132b1a7bf83b4a80…
	https://git.kernel.org/stable/c/20386e7f8d97475b8…
	https://git.kernel.org/stable/c/b33f5741bb187db8f…

Impacted products

Vendor

Product

Version

Linux

Affected: 5800b1cf3fd8ccab752a101865be1e76dac33142 , < 9132b1a7bf83b4a8042fffbc99d075b727a16742 (git)
Affected: 5800b1cf3fd8ccab752a101865be1e76dac33142 , < 20386e7f8d97475b8d815873e246423317ec4260 (git)
Affected: 5800b1cf3fd8ccab752a101865be1e76dac33142 , < b33f5741bb187db8ff32e8f5b96def77cc94dfca (git)

Linux

Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.23 , ≤ 6.18.* (semver)
Unaffected: 6.19.13 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/trace/events/rxrpc.h",
            "net/rxrpc/conn_event.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9132b1a7bf83b4a8042fffbc99d075b727a16742",
              "status": "affected",
              "version": "5800b1cf3fd8ccab752a101865be1e76dac33142",
              "versionType": "git"
            },
            {
              "lessThan": "20386e7f8d97475b8d815873e246423317ec4260",
              "status": "affected",
              "version": "5800b1cf3fd8ccab752a101865be1e76dac33142",
              "versionType": "git"
            },
            {
              "lessThan": "b33f5741bb187db8ff32e8f5b96def77cc94dfca",
              "status": "affected",
              "version": "5800b1cf3fd8ccab752a101865be1e76dac33142",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/trace/events/rxrpc.h",
            "net/rxrpc/conn_event.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.23",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.23",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.13",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix use of wrong skb when comparing queued RESP challenge serial\n\nIn rxrpc_post_response(), the code should be comparing the challenge serial\nnumber from the cached response before deciding to switch to a newer\nresponse, but looks at the newer packet private data instead, rendering the\ncomparison always false.\n\nFix this by switching to look at the older packet.\n\nFix further[1] to substitute the new packet in place of the old one if\nnewer and also to release whichever we don\u0027t use."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-24T14:44:54.024Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9132b1a7bf83b4a8042fffbc99d075b727a16742"
        },
        {
          "url": "https://git.kernel.org/stable/c/20386e7f8d97475b8d815873e246423317ec4260"
        },
        {
          "url": "https://git.kernel.org/stable/c/b33f5741bb187db8ff32e8f5b96def77cc94dfca"
        }
      ],
      "title": "rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31640",
    "datePublished": "2026-04-24T14:44:54.024Z",
    "dateReserved": "2026-03-09T15:48:24.125Z",
    "dateUpdated": "2026-04-24T14:44:54.024Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

FKIE_CVE-2026-31640

CVE-2026-31640 (GCVE-0-2026-31640)

Tags

Sightings

Nomenclature