CVE-2026-119205
mediumpypdf is a free and open-source pure-python PDF library.
Vendor / product: Py-pdf — pypdf
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop when cloning or duplicating a crafted cyclic DictionaryObject. Clone traversal checked generated destination references rather than the original source references, allowing some source cycles to evade the visited-object check. This issue is fixed in version 6.21.4.
CVSS
5.5
5.5 (CVSS v3.1)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-10-29 21:17
Modified: 2026-11-02 16:06
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-11-03 07:35 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
py-pdf / pypdf <6.21.4
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/py-pdf/pypdf/commit/f176db1a1f7f9af3e472e69a843ef1175653b044
Patch / mitigation: https://github.com/py-pdf/pypdf/pull/4288
Patch / mitigation: https://github.com/py-pdf/pypdf/security/advisories/GHSA-mfr5-77xh-9j7h
References
- https://github.com/py-pdf/pypdf/commit/f176db1a1f7f9af3e472e69a843ef1175653b044 security-advisories@github.com
- https://github.com/py-pdf/pypdf/pull/4288 security-advisories@github.com
- https://github.com/py-pdf/pypdf/releases/tag/6.21.4 security-advisories@github.com
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-mfr5-77xh-9j7h security-advisories@github.com
Data sources
NVD CVE API 2.0 — fetched 2026-11-03 07:35 UTC · record ↗