Status: UPDATED | Advisory ID: CVE-2026-31630
| CVE | CVE-2026-31630 |
| CVSS Score / Version | |
| Updated | 2026-10-15 |
| CVSS Vector | |
| CVSS Prose | |
| Affected products | |
| Exploitation prediction (EPSS) |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Linux | Linux Kernel | ||
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem |
| Subsystems | Controllers & Field I/O, OT Supporting Infrastructure |
| Sectors | All Sectors |
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 (NVD)
Monitor Linux's and Siemens's web pages for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-31630 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-31630 |