CVE-2026-4539 MEDIUM

CVE-2026-4539: pygments archetype.py AdlLexer redos

Vendor N/A
Product pygments
Weakness CWE-1333
Published March 22, 2026
Last update March 23, 2026

CVSS base score

4.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

A security flaw has been discovered in pygments up to 2.19.2. The impacted element is the function AdlLexer of the file pygments/lexers/archetype.py. The manipulation results in inefficient regular expression complexity. The attack is only possible with local access. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

Key dates

02Disclosure timeline

March 22, 2026 CVE published
March 23, 2026 Record updated