Vulnerability-Lookup

GHSA-9G7X-MW42-QJMH

Vulnerability from github – Published: 2026-04-24 15:32 – Updated: 2026-06-01 18:31

Details

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

rxrpc: proc: size address buffers for %pISpc output

The AF_RXRPC procfs helpers format local and remote socket addresses into fixed 50-byte stack buffers with "%pISpc".

That is too small for the longest current-tree IPv6-with-port form the formatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a dotted-quad tail not only for v4mapped addresses, but also for ISATAP addresses via ipv6_addr_is_isatap().

As a result, a case such as

is possible with the current formatter. That is 50 visible characters, so 51 bytes including the trailing NUL, which does not fit in the existing char[50] buffers used by net/rxrpc/proc.c.

Size the buffers from the formatter's maximum textual form and switch the call sites to scnprintf().

Changes since v1: - correct the changelog to cite the actual maximum current-tree case explicitly - frame the proof around the ISATAP formatting path instead of the earlier mapped-v4 example

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-2026-31630"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-24T15:16:42Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter\u0027s maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example",
  "id": "GHSA-9g7x-mw42-qjmh",
  "modified": "2026-06-01T18:31:28Z",
  "published": "2026-04-24T15:32:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31630"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/235b2115de892eab2e107a42efa7a4347baaa80b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/386c86412608d3449006a318a662cbcd6ca1f668"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/625af53a1564e31bb2df9adc3739df46137f46c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9"
    }
  ],
  "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-2026-31630 (GCVE-0-2026-31630)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:44 – Updated: 2026-06-01 16:13

Title

rxrpc: proc: size address buffers for %pISpc output

Summary

In the Linux kernel, the following vulnerability has been resolved: rxrpc: proc: size address buffers for %pISpc output The AF_RXRPC procfs helpers format local and remote socket addresses into fixed 50-byte stack buffers with "%pISpc". That is too small for the longest current-tree IPv6-with-port form the formatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a dotted-quad tail not only for v4mapped addresses, but also for ISATAP addresses via ipv6_addr_is_isatap(). As a result, a case such as [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535 is possible with the current formatter. That is 50 visible characters, so 51 bytes including the trailing NUL, which does not fit in the existing char[50] buffers used by net/rxrpc/proc.c. Size the buffers from the formatter's maximum textual form and switch the call sites to scnprintf(). Changes since v1: - correct the changelog to cite the actual maximum current-tree case explicitly - frame the proof around the ISATAP formatting path instead of the earlier mapped-v4 example

Severity

7.8 (High)


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

Assigner

Linux

References

6 references

URL	Tags
https://git.kernel.org/stable/c/386c86412608d3449…
https://git.kernel.org/stable/c/235b2115de892eab2…
https://git.kernel.org/stable/c/625af53a1564e31bb…
https://git.kernel.org/stable/c/db297c78ce537c9ac…
https://git.kernel.org/stable/c/10ebed83f9f6414af…
https://git.kernel.org/stable/c/a44ce6aa2efb61fe4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < 386c86412608d3449006a318a662cbcd6ca1f668 (git) Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < 235b2115de892eab2e107a42efa7a4347baaa80b (git) Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < 625af53a1564e31bb2df9adc3739df46137f46c1 (git) Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < db297c78ce537c9ac96f0eda9b25ad72c8caefa9 (git) Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < 10ebed83f9f6414af4e85bc85ffaeda7effdd874 (git) Affected: 75b54cb57ca34cbe7a87c6ac757c55360a624590 , < a44ce6aa2efb61fe44f2cfab72bb01544bbca272 (git)
Linux	Linux	Affected: 4.9 Unaffected: 0 , < 4.9 (semver) Unaffected: 5.10.258 , ≤ 5.10.* (semver) Unaffected: 5.15.209 , ≤ 5.15.* (semver) Unaffected: 6.1.175 , ≤ 6.1.* (semver) Unaffected: 6.18.23 , ≤ 6.18.* (semver) Unaffected: 6.19.13 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/rxrpc/proc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "versionType": "semver"
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              "status": "unaffected",
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              "versionType": "semver"
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              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.1.175",
              "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": [
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          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.258",
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                  "vulnerable": true
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter\u0027s maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example"
        }
      ],
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            "baseSeverity": "HIGH",
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        {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31630",
    "datePublished": "2026-04-24T14:44:46.606Z",
    "dateReserved": "2026-03-09T15:48:24.124Z",
    "dateUpdated": "2026-06-01T16:13:03.129Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

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.

Action not permitted

GHSA-9G7X-MW42-QJMH

CVE-2026-31630 (GCVE-0-2026-31630)

Tags

Sightings

Nomenclature