CVE-2026-102997CWE-400CWE-407denial-of-service

CVE-2026-102997

High · published October 1, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
26.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
8.7 · 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
EPSS
0.00345 · 26.8th percentile
Weaknesses
CWE-400 · Uncontrolled Resource Consumption; CWE-407 · Inefficient Algorithmic Complexity
Published
2026-10-01T01:17Z
Affected products (1)
ProductVersionsFixed in
pypdf_project/pypdf< 6.18.16.18.1
References (4)
https://github.com/py-pdf/pypdf/commit/d9d38cf99b115deb562d3b68f36c33027bc04f79 · [email protected]https://github.com/py-pdf/pypdf/pull/4073 · [email protected]https://github.com/py-pdf/pypdf/releases/tag/6.18.1 · [email protected]https://github.com/py-pdf/pypdf/security/advisories/GHSA-jw7q-gvrg-4vj3 · [email protected]
EPSS history
Timeline
  • 02 OCT 03:41Z
    EPSS moved — → 1%
    epss
  • 30 SEP 20:05Z
    pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
    cvelistv5