CVE-2026-74634: Linux kernel · ring-buffer: Prevent subbuf order change when resizing is disabled
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 22 Aug 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
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 fix has been implemented in the Linux kernel to prevent sub-buffer order changes when resizing is disabled by returning an error code instead of freeing buffer pages. Users should apply the official Linux kernel updates that include this patch to remediate the vulnerability. No additional mitigation is indicated beyond applying the patch.
Description
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Prevent subbuf order change when resizing is disabled Because ring_buffer_subbuf_order_set() frees buffer pages, we can't allow it when resizing is disabled. A non-consuming reader is at risk of use-after-free (rb_advance_iter()). Return -EBUSY on resize_disabled, matching ring_buffer_resize() behaviour.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74634 (opens in a new tab)
- git.kernel.org/stable/c/62978cf6347972c04130e4e841ba404504d92b32 (opens in a new tab)
- git.kernel.org/stable/c/7568e9e717e7540bd05bcc007f5d76fcaff3cdff (opens in a new tab)
- git.kernel.org/stable/c/b45b91db41379ee5fb36c187d6d7c37b725cbe8e (opens in a new tab)
- git.kernel.org/stable/c/bf98d7b0d5a99991e47e66cee4eb1d3fa514be97 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74634 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74634 (opens in a new tab)