PyPy pyexpat ExternalEntityParserCreate Use-After-Free
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.
CVE-2026-76875
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-76875
PyPy
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/pypy/pypy",
"vendor": "PyPy",
"product": "PyPy",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "3.11.16",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.12.0",
"lessThan": "3.12.14",
"versionType": "semver"
}
],
"packageURL": "pkg:github/pypy/pypy",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-76875
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #7887 · Revision 1
- Added to Heist Feed
- Publisher date