CVE-2026-31656: Linux kernel · drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in ca3f48c3567dd49efdc55b80029ae74659c682ee : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in ca3f48c3567dd49efdc55b80029ae74659c682ee, a00e92bf6583d019a4fb2c2df7007e6c9b269ce7, 82034799c6c14b3104668878c3f3e5786f777126 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in the Linux kernel. The patch replaces non-atomic pointer operations with atomic xchg() to prevent the race condition. Users should update to a Linux kernel version that includes the fix identified by the listed commit hashes. No additional mitigation is required once patched.
Description
CVE-2026-31656 is a high-severity vulnerability in the Linux kernel's Intel i915 graphics driver. It involves a race condition causing a reference count underflow in the intel_engine_park_heartbeat function. This occurs when concurrent operations on the engine heartbeat request lead to a double release of the same resource, potentially causing use-after-free conditions. The issue is fixed by making the pointer update atomic using xchg(), preventing concurrent callers from releasing the same resource twice.
References
- git.kernel.org/stable/c/82034799c6c14b3104668878c3f3e5786f777126 (opens in a new tab)
- git.kernel.org/stable/c/70d3e622b10092fc483e28e57b4e8c49d9cc7f68 (opens in a new tab)
- git.kernel.org/stable/c/8ce44d28a84fd5e053a88b04872a89d95c0779d4 (opens in a new tab)
- git.kernel.org/stable/c/ca3f48c3567dd49efdc55b80029ae74659c682ee (opens in a new tab)
- git.kernel.org/stable/c/a00e92bf6583d019a4fb2c2df7007e6c9b269ce7 (opens in a new tab)
- git.kernel.org/stable/c/2af8b200cae3fdd0e917ecc2753b28bb40c876c1 (opens in a new tab)
- git.kernel.org/stable/c/455d98ed527fc94eed90406f90ab2391464ca657 (opens in a new tab)
- git.kernel.org/stable/c/4c71fd099513bfa8acab529b626e1f0097b76061 (opens in a new tab)