Use-After-Free in Linux kernel (CVE-2026-31731)
Summary
Vulnerability in Linux kernel (CVE-2026-31731). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
thermal: core: Address thermal zone removal races with resume
Since thermal_zone_pm_complete() and thermal_zone_device_resume()
re-initialize the poll_queue delayed work for the given thermal zone,
the cancel_delayed_work_sync() in thermal_zone_device_unregister()
may miss some already running work items and the thermal zone may
be freed prematurely [1].
There are two failing scenarios that both start with
running thermal_pm_notify_complete() right before invoking
thermal_zone_device_unregister() for one of the thermal zones.
In the first scenario, there is a work item already running for
the given thermal zone when thermal_pm_notify_complete() calls
thermal_zone_pm_complete() for that thermal zone and it continues to
run when thermal_zone_device_unregister() starts. Since the poll_queue
delayed work has been re-initialized by thermal_pm_notify_complete(), the
running work item will be missed by the cancel_delayed_work_sync() in
thermal_zone_device_unregister() and if it continues to run past the
freeing of the thermal zone object, a use-after-free will occur.
In the second scenario, thermal_zone_device_resume() queued up by
thermal_pm_notify_complete() runs right after the thermal_zone_exit()
called by thermal_zone_device_unregister() has returned. The poll_queue
delayed work is re-initialized by it before cancel_delayed_work_sync() is
called by thermal_zone_device_unregister(), so it may continue to…
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-31731 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-31731" on the vendor's site.
CVE-2026-31731 (Linux kernel) — CWE-416 / CVSS v3 7.8
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Use-after-free (CWE-416) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-31731 linux-lts Fixed in: 6.12.85-r0
- Debian DEBIAN-CVE-2026-31731 linux Fixed in: 6.12.85-1
- Ubuntu UBUNTU-CVE-2026-31731 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org