CVE-2026-31630
What it is
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
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-121
- Record status
- Modified
Affected
- Linux Kernel < 6.18.23
- Linux Kernel < 6.19.13
- Linux Kernel 4.9
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31630.md and follow it. Check whether this project is affected by CVE-2026-31630. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874
- https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272
- https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9
References
- https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874
- https://git.kernel.org/stable/c/235b2115de892eab2e107a42efa7a4347baaa80b
- https://git.kernel.org/stable/c/386c86412608d3449006a318a662cbcd6ca1f668
- https://git.kernel.org/stable/c/625af53a1564e31bb2df9adc3739df46137f46c1
- https://git.kernel.org/stable/c/808a34cdbe8ce336c202d8ea6d5e48496764dc37
- https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272
- https://git.kernel.org/stable/c/a6042b8066b24dbcc7945616a157d4d43e463668
- https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html