CVE-2026-76957ModerateLocalRevised 24 Aug
libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.
Assessment
- Severity
- Moderate
- CVSS base score
- 4.9CVSS:3.1/
AV:L/ AC:H/ PR:N/ UI:N/ S:U/ C:L/ I:L/ A:L/ E:U - Impact
- Not stated
- EPSS, next 30 days
- Not scored yet
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Not assessed
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Mariner
- Weakness
- CWE-416: Use After Free
- Issued by
- mitre
- Published
- 21 Aug 2026 · August 2026
- Last revised
- 24 Aug 2026Information published.
CVSS 3.1 base metricsRed raises the risk · green lowers it
- Attack vector
- LocalAV:L
- Attack complexity
- HighAC:H
- Privileges required
- NonePR:N
- User interaction
- NoneUI:N
- Scope
- UnchangedS:U
- Confidentiality
- LowC:L
- Integrity
- LowI:L
- Availability
- LowA:L
Updates that fix it
0 KBsNo KB listed
MSRC lists no downloadable update, which usually means a service-side fix or a release-notes update. Check the MSRC advisory.
Affected products
3 affected products
- azl3 cmake 3.30.3-15 on Azure Linux 3.0
- azl3 expat 2.8.2-1 on Azure Linux 3.0
- azl3 python3 3.12.9-14 on Azure Linux 3.0
What changed
First observed 14 Oct 2026- 14 Oct 2026 Source coverage: msrc-cvrfIncomplete → Current
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