CVE-2021-20270

Publication date 9 March 2021

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Status

Package Ubuntu Release Status
pygments 23.04 lunar
Fixed 2.7.1+dfsg-2
22.10 kinetic
Fixed 2.7.1+dfsg-2
22.04 LTS jammy
Fixed 2.7.1+dfsg-2
21.10 impish
Fixed 2.7.1+dfsg-2
21.04 hirsute
Fixed 2.7.1+dfsg-2
20.10 groovy
Fixed 2.3.1+dfsg-4ubuntu0.1
20.04 LTS focal
Fixed 2.3.1+dfsg-1ubuntu2.1
18.04 LTS bionic
Fixed 2.2.0+dfsg-1ubuntu0.1
16.04 LTS xenial
Fixed 2.1+dfsg-1ubuntu0.1
14.04 LTS trusty
Fixed 1.6+dfsg-1ubuntu1.1+esm1

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
pygments

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-4897-2
    • Pygments vulnerabilities
    • 14 August 2023

Other references