What is CVE-2026-71870?

CVE-2026-71870 is a low-severity vulnerability in Py-Pdf Pypdf, classified under Uncontrolled Resource Consumption. CVSS score: 3.3/10. Published 2026-08-07.

How severe is CVE-2026-71870?

Low severity. CVSS v3 base score is 3.3 out of 10.

Resource exhaustion in Py-Pdf Pypdf

CVE-2026-71870

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause large memory consumption when pypdf/_cmap.py function parse_bfrange parses unusually large source-code or destination-string tokens in a font /ToUnicode CMap during text extraction. This issue is fixed in 6.15.0.

Vulnerability class: DoS (Denial of Service)

Published 2026-08-07 · last modified 2026-11-02.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.001 (2.2th percentile), scored 2026-11-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 2.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Py-Pdf Pypdf — versions < 6.15.0
Pypdf Project

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

github.com/py-pdf/pypdf/security/advisories/GHSA-fp3f-mc75-235c (Patch, Vendor Advisory)
github.com/py-pdf/pypdf/pull/3944 (Patch)
github.com/py-pdf/pypdf/commit/afba8080e19d29a3c256a742b340995e695b35aa (Patch)
github.com/py-pdf/pypdf/releases/tag/6.15.0 (Release Notes)

Frequently asked questions

What is CVE-2026-71870?: CVE-2026-71870 is a low-severity vulnerability in Py-Pdf Pypdf, classified under Uncontrolled Resource Consumption. CVSS score: 3.3/10. Published 2026-08-07.
How severe is CVE-2026-71870?: Low severity. CVSS v3 base score is 3.3 out of 10.