XXE in Py-Pdf Pypdf
CVE-2026-40260
pypdf is a free and open-source pure-python PDF library. In versions prior to 6.10.0, manipulated XMP metadata entity declarations can exhaust RAM. An attacker who exploits this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the XMP metadata. This issue has been fixed in version 6.10.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (41.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Py-Pdf Pypdf — versions < 6.10.0
- Pypdf Project
Weakness classification (CWE)
References
- github.com/py-pdf/pypdf/security/advisories/GHSA-3crg-w4f6-42mx (Patch, Mitigation, Vendor Advisory)
- github.com/py-pdf/pypdf/pull/3724 (Patch, Issue Tracking)
- github.com/py-pdf/pypdf/commit/b15a374e5ca648d4878e57c3b2c0551e7f8cc7f8 (Patch)
- github.com/py-pdf/pypdf/releases/tag/6.10.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-40260?
- CVE-2026-40260 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Improper Restriction of Recursive Entity References in DTDs (XML Entity Expansion). CVSS score: 5.3/10. Published 2026-04-17.
- How severe is CVE-2026-40260?
- Medium severity. CVSS v3 base score is 5.3 out of 10.