CVE-2026-31630
Description
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
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | fixed | 6.19.13-1 |
| debian | sid | fixed | 6.19.13-1 |
| debian | trixie | affected | |
| linux-kernel | affected | 6.18.23 | |
| linux-kernel | 4.9 | affected | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874
- https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272
- https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9
- https://www.suse.com/security/cve/CVE-2026-31630.html
- https://security-tracker.debian.org/tracker/CVE-2026-31630
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.