CVE-2026-102997

high

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while the earlier recovery counter fails to advance for bytes that successfully decode, causing long runtimes and application unavailability. This is a residual issue after the malformed FlateDecode recovery fix. This issue is fixed in version 6.18.1.

References

https://github.com/py-pdf/pypdf/security/advisories/GHSA-jw7q-gvrg-4vj3

https://github.com/py-pdf/pypdf/releases/tag/6.18.1

https://github.com/py-pdf/pypdf/pull/4073

https://github.com/py-pdf/pypdf/commit/d9d38cf99b115deb562d3b68f36c33027bc04f79

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-90373

Details

Source: Mitre, NVD

Published: 2026-09-30

Updated: 2026-10-02

Named Vulnerability: GHSA-jw7q-gvrg-4vj3

Risk Information

CVSS v2

Base Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 6.5

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

Severity: Medium

CVSS v4

Base Score: 8.7

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

Severity: High

EPSS

EPSS: 0.00524