{"id":"CVE-2026-76875","published":"2026-09-29T13:17:52.280","lastModified":"2026-09-29T21:35:07.960","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.","cvssScore":5.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cwes":["CWE-416"],"vendors":[],"products":[],"references":[{"url":"https://doc.pypy.org/release-v8.0.0.html","tags":[]},{"url":"https://github.com/pypy/pypy/releases/tag/release-pypy3.11-v8.0.0","tags":[]},{"url":"https://github.com/pypy/pypy/releases/tag/release-pypy3.12-v8.0.0","tags":[]},{"url":"https://www.vulncheck.com/advisories/pypy-pyexpat-externalentityparsercreate-use-after-free","tags":[]}],"exploitRefs":[{"url":"https://github.com/pypy/pypy/releases/tag/release-pypy3.11-v8.0.0","tags":[]},{"url":"https://github.com/pypy/pypy/releases/tag/release-pypy3.12-v8.0.0","tags":[]}],"hasPoc":true,"ai":null}