Vulnerability in Py-Pdf Pypdf
CVE-2026-24688
pypdf is a free and open-source pure-python PDF library. An attacker who uses an infinite loop vulnerability that is present in versions prior to 6.6.2 can craft a PDF which leads to an infinite loop. This requires accessing the outlines/bookmarks. This has been fixed in pypdf 6.6.2. If projects cannot upgrade yet, consider applying the changes from PR #3610 manually.
EPSS: 0.004 (31.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.
Affected products
- Py-pdf Pypdf — versions < 6.6.2
- Pypdf_project Pypdf
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-24688?
- CVE-2026-24688 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 4.3/10. Published 2026-01-27.
- How severe is CVE-2026-24688?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2026-24688 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.