CVE-2026-31482
Medium
Description
In the Linux kernel, the following vulnerability has been resolved: s390/entry: Scrub r12 register on kernel entry Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"), all entry handlers loaded r12 with the current task pointer (lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That commit removed TIF_ISOLATE_BP, dropping both the branch prediction macros and the r12 load, but did not add r12 to the register clearing sequence. Add the missing xgr %r12,%r12 to make the register scrub consistent across all entry points.
SeverityMedium
CVSS5.5
Exploit probability—
Product
Linux Kernel
PublishedApr 22, 2026
First seenApr 22, 2026
How to fix
Update
- linux linux_kernel6.6.131, 6.12.80, 6.18.21, 6.19.11 or later
Patches
- git.kernel.org/stable/c/0738d395aab8fae3b5a3ad3fc640630c91693c27
- git.kernel.org/stable/c/7f4e3233faa8470dd0627bc49b2809f2bfebd909
- git.kernel.org/stable/c/95c899cd791803a5bf7b73e5994fbbe1cc1a9c36
- git.kernel.org/stable/c/99a8b420f3f0e162eb9c9c9253929d4d23f9bd30
- git.kernel.org/stable/c/a58d298a83a3a9b7ca99ded9d60a1e77231159ef
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 6.4.1 ≤ v < 6.6.131, 6.7 ≤ v < 6.12.80, 6.13 ≤ v < 6.18.21, 6.19 ≤ v < 6.19.11, 6.4, 7.0 | 6.6.131, 6.12.80, 6.18.21, 6.19.11 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.