CVE-2026-76875 (GCVE-0-2026-76875)

Vulnerability from cvelistv5 – Published: 2026-09-29 12:45 – Updated: 2026-10-02 12:07 X_Open Source
VLAI
Title
PyPy pyexpat ExternalEntityParserCreate Use-After-Free
Summary
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.
Severity
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
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-02 12:07 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version
PyPy PyPy Affected: 0 , < 3.11.16 (semver)
Affected: 3.12.0 , < 3.12.14 (semver)
Create a notification for this product.
Date Public
2026-09-19 00:00
Credits
Fabian Wahle (Hap Security) VulnCheck
Show details on NVD website
To clipboard 

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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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