CVE-2026-31630

High

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

Package Linux Kernel
Published 2026-04-24
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 4.9 and later are affected. Fixed in 5.10.258, 5.15.209, 6.1.175, 6.18.23, 6.19.13, 7.0 and their respective stable series.

Affected from
≥ 4.9
Fixed in
✓ 5.10.258 5.10.x ✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.18.23 6.18.x ✓ 6.19.13 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31630 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

6 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31630?

    CVE-2026-31630 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 4.9 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31630 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31630?

    CVE-2026-31630 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-31630?

    Yes — CVE-2026-31630 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 4.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31630 actively exploited?

    No — CVE-2026-31630 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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