CVE-2026-27026
February 19, 2026
Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed "/FlateDecode" stream, where the byte-by-byte decompression is used. Patches This has been fixed in "pypdf==6.7.1" (https://github.com/py-pdf/pypdf/releases/tag/6.7.1). Workarounds If you cannot upgrade yet, consider applying the changes from PR "#3644" (https://github.com/py-pdf/pypdf/pull/3644).
Affected Packages
https://github.com/py-pdf/pypdf.git (GITHUB):
Affected version(s) >=1.26.0 <6.7.1Fix Suggestion:
Update to version 6.7.1pypdf (PYTHON):
Affected version(s) >=1.0 <6.7.1Fix Suggestion:
Update to version 6.7.1Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.2
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
