CVE-2026-52936: Linux kernel · crypto: jitterentropy – replace long-held spinlock with mutex
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1061.64~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1061.64~22.04.1, 6.8.0-1063.71~22.04.1, 6.8.0-1062.69~22.04.1 +44
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jun 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 |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| 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 patch is available and has been released in linux-aws kernel versions 6.8.0-1058.61~22.04.1 and later. Users should upgrade to these fixed versions to remediate the issue. No additional mitigation actions are required as the fix replaces the spinlock with a mutex to prevent stalls.
Description
A vulnerability in the Linux kernel's crypto jitterentropy subsystem was resolved by replacing a long-held spinlock with a mutex to prevent stalls caused by contending readers spinning on the same lock during expensive entropy generation. This issue affected specific linux-aws kernel versions and could cause availability impact due to stalls. The vulnerability is fixed in later kernel versions.
References
- ubuntu.com/security/CVE-2026-52936 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-52936 (opens in a new tab)
- git.kernel.org/linus/01d798e9feb30212952d4e992801ba6bd6a82351 (opens in a new tab)
- git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351 (opens in a new tab)
- git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4 (opens in a new tab)
- git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4 (opens in a new tab)
- git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02 (opens in a new tab)
- git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880 (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)