CVE-2026-31482
Published: April 22, 2026· Updated: Apr 28, 2026
Official 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.
Technical Analysis
CVE-2026-31482 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (5)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31482 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts