CVE-2026-76875PyPy pyexpat ExternalEntityParserCreate Use-After-Free
Updated under an hour ago ()
Does this affect you?
It affects PyPy. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weakness (CWE)
- CWE-416
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 2, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
PyPy PyPy pypy:pypy (from the name) | before 3.11.16; from 3.12.0 before 3.12.14 | CNA record |
References
- https://doc.pypy.org/release-v8.0.0.htmlrelease-notes
- https://github.com/pypy/pypy/releases/tag/release-pypy3.12-v8.0.0patch
- https://github.com/pypy/pypy/releases/tag/release-pypy3.11-v8.0.0patch
- https://www.vulncheck.com/advisories/pypy-pyexpat-externalentityparsercreate-use-after-freethird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.