CVE-2026-52943: Linux kernel · Use After Free
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +67
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 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 fix is available and included in Linux kernel versions 5.15.0-1117.124~20.04.1 and later listed fixed versions. Users should update to these or later patched kernel releases to remediate this vulnerability. No additional mitigations are required once patched.
Description
A use-after-free vulnerability in the Linux kernel's network skbuff subsystem (pskb_carve helpers) was fixed. The flaw involved missing reference counting for zerocopy buffers, leading to premature freeing of memory still in use. This vulnerability allows local unprivileged users to escalate privileges to root. The issue affects multiple Azure Linux kernel versions prior to the fixed releases. A patch is available and included in several 5.15 kernel updates.
References
- ubuntu.com/security/CVE-2026-52943 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-52943 (opens in a new tab)
- git.kernel.org/linus/98d0912e9f841e5529a5b89a972805f34cb1c69d (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-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-52943 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-52943 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2492137 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- git.kernel.org/stable/c/2e0e74c59b2761a414d9f48d7bee1e45220b2427 (opens in a new tab)
- git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18 (opens in a new tab)
- git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37 (opens in a new tab)
- git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6 (opens in a new tab)
- git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d (opens in a new tab)
- git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578 (opens in a new tab)
- git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f (opens in a new tab)
- git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52943.json (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)