CVEvulnerability
CVE-2026-76875
6.3 MEDIUM
Official page ↗
- Status
- Awaiting Analysis
- Published
- 2026-09-29
- Last modified
- 2026-10-02
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 6.3 MEDIUM — 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weaknesses
- CWE-416
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.
Related
Weakness · CWE (1)
- CWE-416 Use After Free weakness
References
- https://doc.pypy.org/release-v8.0.0.html doc.pypy.org
- https://github.com/pypy/pypy/releases/tag/release-pypy3.11-v8.0.0 github.com
- https://github.com/pypy/pypy/releases/tag/release-pypy3.12-v8.0.0 github.com
- https://www.vulncheck.com/advisories/pypy-pyexpat-externalentityparsercreate-use-after-free www.vulncheck.com