CyberSecBulletin
CVE-2026-31528NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-31528 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 656f35b463995bee024d948440128230aacd81e1, 3a696e84a8b1fafdd774bb30d62919faf844d9e4, 35f7914e54fe7f13654c22ee045b05e4b6d8062b as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 656f35b463995bee024d948440128230aacd81e1 or 3a696e84a8b1fafdd774bb30d62919faf844d9e4 or 35f7914e54fe7f13654c22ee045b05e4b6d8062b or 4c759446046500a1a6785b25725725c3ff087ace, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.131 or 6.12.80 or 6.18.21 or 6.19.11, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxbd27568117664b8b3e259721393df420ed51f57b up to, but not including, 656f35b463995bee024d948440128230aacd81e1; bd27568117664b8b3e259721393df420ed51f57b up to, but not including, 3a696e84a8b1fafdd774bb30d62919faf844d9e4; bd27568117664b8b3e259721393df420ed51f57b up to, but not including, 35f7914e54fe7f13654c22ee045b05e4b6d8062b; bd27568117664b8b3e259721393df420ed51f57b up to, but not including, 4c759446046500a1a6785b25725725c3ff087ace; bd27568117664b8b3e259721393df420ed51f57b up to, but not including, 4b9ce671960627b2505b3f64742544ae9801df97; 6.2656f35b463995bee024d948440128230aacd81e1, 3a696e84a8b1fafdd774bb30d62919faf844d9e4, 35f7914e54fe7f13654c22ee045b05e4b6d8062b, 4c759446046500a1a6785b25725725c3ff087ace, 4b9ce671960627b2505b3f64742544ae9801df97
LinuxLinux Kernel6.2 up to, but not including, 6.6.131; 6.7 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 7.06.6.131, 6.12.80, 6.18.21, 6.19.11

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: perf: Make sure to use pmu_ctx->pmu for groups Oliver reported that x86_pmu_del() ended up doing an out-of-bound memory access when group_sched_in() fails and needs to roll back. This *should* be handled by the transaction callbacks, but he found that when the group leader is a software event, the transaction handlers of the wrong PMU are used. Despite the move_group case in perf_event_open() and group_sched_in() using pmu_ctx->pmu. Turns out, inherit uses event->pmu to clone the events, effectively undoing the move_group case for all inherited contexts. Fix this by also making inherit use pmu_ctx->pmu, ensuring all inherited counters end up in the same pmu context. Similarly, __perf_event_read() should use equally use pmu_ctx->pmu for the group case.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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