VulnerabilityPublished 9 Sep 2026Updated 20 Oct 2026

CVE-2026-80916: Linux kernel · kcov: fix data corruption and race conditions on PREEMPT_RT

Affects Linux kernelSource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Sep 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented that moves the temporary storage for KCOV state from the per-CPU area to the per-thread area and addresses kernel crashes related to vmalloc_node() failures. Users should apply the updated Linux kernel versions that include this patch. Since this is a kernel-level fix, upgrading to the patched kernel versions is the recommended remediation.

Description

A vulnerability in the Linux kernel's KCOV subsystem affects PREEMPT_RT kernels, causing data corruption and race conditions due to improper handling of temporary storage for remote KCOV state. The issue arises because temporary storage was allocated per-CPU, leading to overwrites during nested softirq preemption. The fix moves this storage to a per-thread basis, preventing data corruption. Additionally, the patch addresses kernel crashes caused by NULL returns from vmalloc_node() during initialization. This vulnerability affects specific Linux kernel versions used in various Ubuntu releases.

Impact

The vulnerability can cause data corruption in the KCOV state on PREEMPT_RT kernels, potentially affecting kernel tracing and debugging reliability. It also could lead to kernel crashes due to improper handling of memory allocation failures during initialization. There is no indication of active exploitation in the wild. The impact is primarily stability and reliability degradation of the kernel's KCOV functionality.

Summary

The Linux kernel vulnerability (CVE-2026-80916) involves the KCOV subsystem on PREEMPT_RT kernels where temporary storage for saving and restoring remote KCOV state was allocated in the per-CPU area. Nested softirq preemption on the same CPU could overwrite this storage, corrupting the KCOV state. The fix relocates the temporary storage to the per-thread area, ensuring each softirq thread has its own context and preventing overwrites. The patch also retains the per-CPU lock to maintain atomicity during remote KCOV operations. Furthermore, it addresses kernel crashes caused by vmalloc_node() returning NULL in kcov_init(), which previously led to NULL pointer dereferences and memory leaks.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-80916
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:16.04:LTS, Ubuntu:18.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:26.04:LTS

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 03:43 UTC

Technical details

References

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