What is CVE-2026-33699?

CVE-2026-33699 is a high-severity vulnerability in Py-Pdf Pypdf, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2026-03-27.

How severe is CVE-2026-33699?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Py-Pdf Pypdf

CVE-2026-33699

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.

Published 2026-03-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (38.8th percentile), scored 2026-09-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Py-Pdf Pypdf — versions < 6.9.2
Pypdf Project

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

github.com/py-pdf/pypdf/security/advisories/GHSA-87mj-5ggw-8qc3 (Patch, Vendor Advisory)
github.com/py-pdf/pypdf/pull/3693 (Patch, Issue Tracking)
github.com/py-pdf/pypdf/releases/tag/6.9.2 (Product, Release Notes)

Frequently asked questions

What is CVE-2026-33699?: CVE-2026-33699 is a high-severity vulnerability in Py-Pdf Pypdf, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2026-03-27.
How severe is CVE-2026-33699?: High severity. CVSS v3 base score is 7.5 out of 10.