In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.
https://www.debian.org/security/2021/dsa-4889
https://www.debian.org/security/2021/dsa-4878
https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html
https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html
https://lists.debian.org/debian-lts-announce/2021/03/msg00024.html
https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14
https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ce
Published: 2021-03-17
Updated: 2024-11-21
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
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