CVE-2026-102994

pypdf is a free and open-source pure-python PDF library. Prior to 6.18.0, a crafted PDF containing indirect-object identifiers or generation-number tokens that continue for a long time without whitespace can cause pypdf/_reader.py and pypdf/generic/_base.py to scan excessive input through read_until_whitespace, resulting in long runtimes and application unavailability. This issue is fixed in version 6.18.0.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 27% of CVEs (scores of 2026-10-25)

CWEs

CWE-400, CWE-407

Published

2026-09-30

Modified

2026-10-05

Record from

the NVD, synced 2026-10-19

Affected

• pypdf_project:pypdf

Packages (OSV)

References

• https://github.com/py-pdf/pypdf/commit/82501d2993c6387833c4949d205caeb188f8bb9e
• https://github.com/py-pdf/pypdf/pull/4055
• https://github.com/py-pdf/pypdf/releases/tag/6.18.0
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-5jq2-8x83-x246

Check your stackJSON