CVE-2026-24688

low-risk

Published 2026-01-27

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.

Do I need to act?

0.01% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 4.3/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Pypdf

Affected Vendors

Pypdf Project

References (4)

Patch https://github.com/py-pdf/pypdf/commit/b1282f8dcdc1a7b41ceab6740ffddfdf31b1fec1

Issue Tracking https://github.com/py-pdf/pypdf/pull/3610

Product https://github.com/py-pdf/pypdf/releases/tag/6.6.2

Vendor Advisory https://github.com/py-pdf/pypdf/security/advisories/GHSA-2q4j-m29v-hq73

/ 100

low-risk

Severity 18/34 · Moderate

Exploitability 0/34 · Minimal

Exposure 5/34 · Minimal