CVE-2026-76875
Publication date 29 September 2026
Last updated 30 September 2026
Ubuntu priority
Description
PyPy before versions 3.11.16 and 3.12.14 contains a use-after-free vulnerability in the pyexpat module's ExternalEntityParserCreate function that allows attackers to corrupt memory by supplying a crafted XML document to applications that create external-entity sub-parsers without retaining a reference to the parent parser. The child parser retains a raw C back-pointer to the parent parser struct while PyPy's tracing garbage collector can free the parent's C struct, causing bundled libexpat to dereference the freed pointer on every parsed token, producing memory corruption.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| pypy3 | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
Severity score breakdown
CVSS version:
Base score
6.3 · Medium
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Base score
5.3 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-76875
- https://doc.pypy.org/release-v8.0.0.html
- https://github.com/pypy/pypy/releases/tag/release-pypy3.11-v8.0.0
- https://github.com/pypy/pypy/releases/tag/release-pypy3.12-v8.0.0
- https://www.vulncheck.com/advisories/pypy-pyexpat-externalentityparsercreate-use-after-free