{"id":"UBUNTU-CVE-2021-27291","details":"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.","modified":"2026-05-20T16:04:51.875839257Z","published":"2021-03-17T13:15:00Z","related":["USN-4897-1","USN-4897-2"],"upstream":["CVE-2021-27291"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-27291"},{"type":"REPORT","url":"https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ce"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4897-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4897-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-27291"}],"affected":[{"package":{"name":"pygments","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/pygments?arch=source&distro=trusty%2Fesm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6+dfsg-1ubuntu1.1+esm1"}]}],"versions":["1.6+dfsg-1","1.6+dfsg-1build1","1.6+dfsg-1ubuntu1","1.6+dfsg-1ubuntu1.1"],"ecosystem_specific":{"availability":"Available with 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