CVE-2021-20270
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
02 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
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 2.75% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 85.9% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-03-23 16:40Z5 YR AGO
- Last updated
- 2024-08-03 17:37Z2 YR AGO
- Reserved
- 2020-12-17
- Assigning CNA
- redhat
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')Base
- Data version
- 5.1
- Document digest
- b67c705a4ab3fc73bfd38369cd610eef9f618cf7c584324a2c99796df85c67b4
05 Affected products
06 References
- bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1922136
- www.debian.orgDSA-4889https://www.debian.org/security/2021/dsa-4889
- lists.debian.org[debian-lts-announce] 20210505 [SECURITY] [DLA 2648-1] mediawiki security updatehttps://lists.debian.org/debian-lts-announce/2021/05/msg00003.html
- lists.debian.org[debian-lts-announce] 20210506 [SECURITY] [DLA 2648-2] mediawiki regression updatehttps://lists.debian.org/debian-lts-announce/2021/05/msg00006.html
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
07 Fixed in
AlmaLinux 8
- babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python-nose-docs Fixed
A version is affected if any line below covers it.
- Affected before 1.3.7-31.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.7-31.module_el8.6.0+2781+fed64c13
- python-psycopg2-doc Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python-pymongo-doc Fixed
A version is affected if any line below covers it.
- Affected before 3.7.0-1.module_el8.5.0+135+5ce32bc4
- Affected before 3.7.0-1.module_el8.5.0+2569+5c5719bc
- python-sqlalchemy-doc Fixed
A version is affected if any line below covers it.
- Affected before 1.3.2-2.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.2-2.module_el8.6.0+2781+fed64c13
- python-virtualenv-doc Fixed
A version is affected if any line below covers it.
- Affected before 15.1.0-21.module_el8.5.0+135+5ce32bc4
- Affected before 15.1.0-21.module_el8.5.0+2569+5c5719bc
- python2-Cython Fixed in 0.28.1-7.module_el8.6.0+2781+fed64c13
- python2-PyMySQL Fixed in 0.8.0-10.module_el8.6.0+2781+fed64c13
- python2-attrs Fixed in 17.4.0-10.module_el8.6.0+2781+fed64c13
- python2-babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python2-backports Fixed in 1.0-16.module_el8.6.0+2781+fed64c13
- python2-backports-ssl_match_hostname Fixed in 3.5.0.1-12.module_el8.6.0+2781+fed64c13
- python2-bson Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-chardet Fixed in 3.0.4-10.module_el8.6.0+2781+fed64c13
- python2-coverage Fixed in 4.5.1-4.module_el8.6.0+2781+fed64c13
- python2-dns Fixed in 1.15.0-10.module_el8.6.0+2781+fed64c13
- python2-docs Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docs-info Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docutils Fixed in 0.14-12.module_el8.6.0+2781+fed64c13
- python2-funcsigs Fixed in 1.0.2-13.module_el8.6.0+2781+fed64c13
- python2-idna Fixed in 2.5-7.module_el8.6.0+2781+fed64c13
- python2-ipaddress Fixed in 1.0.18-6.module_el8.6.0+2781+fed64c13
- python2-jinja2 Fixed in 2.10-9.module_el8.6.0+2781+fed64c13
- python2-markupsafe Fixed in 0.23-19.module_el8.6.0+2781+fed64c13
- python2-mock Fixed in 2.0.0-13.module_el8.6.0+2781+fed64c13
- python2-nose Fixed in 1.3.7-31.module_el8.6.0+2781+fed64c13
- python2-numpy Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-doc Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-f2py Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-pluggy Fixed in 0.6.0-8.module_el8.6.0+2781+fed64c13
- python2-psycopg2 Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-debug Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-tests Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-py Fixed in 1.5.3-6.module_el8.6.0+2781+fed64c13
- python2-pygments Fixed in 2.2.0-22.module_el8.6.0+2781+fed64c13
- python2-pymongo Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-pymongo-gridfs Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-pysocks Fixed in 1.6.8-6.module_el8.6.0+2781+fed64c13
- python2-pytest Fixed in 3.4.2-13.module_el8.6.0+2781+fed64c13
- python2-pytest-mock Fixed in 1.9.0-4.module_el8.6.0+2781+fed64c13
36 further packages in AlmaLinux 8 not shown (first 40 listed).
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Arch Linux
- mediawiki Fixed in 1.35.2-1
- python-pygments Fixed in 2.7.4-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
CloudLinux 8
- babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python-nose-docs Fixed
A version is affected if any line below covers it.
- Affected before 1.3.7-31.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.7-31.module_el8.6.0+2781+fed64c13
- python-psycopg2-doc Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python-pymongo-doc Fixed
A version is affected if any line below covers it.
- Affected before 3.7.0-1.module_el8.5.0+135+5ce32bc4
- Affected before 3.7.0-1.module_el8.5.0+2569+5c5719bc
- python-sqlalchemy-doc Fixed
A version is affected if any line below covers it.
- Affected before 1.3.2-2.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.2-2.module_el8.6.0+2781+fed64c13
- python-virtualenv-doc Fixed
A version is affected if any line below covers it.
- Affected before 15.1.0-21.module_el8.5.0+135+5ce32bc4
- Affected before 15.1.0-21.module_el8.5.0+2569+5c5719bc
- python2-Cython Fixed in 0.28.1-7.module_el8.6.0+2781+fed64c13
- python2-PyMySQL Fixed in 0.8.0-10.module_el8.6.0+2781+fed64c13
- python2-attrs Fixed in 17.4.0-10.module_el8.6.0+2781+fed64c13
- python2-babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python2-backports Fixed in 1.0-16.module_el8.6.0+2781+fed64c13
- python2-backports-ssl_match_hostname Fixed in 3.5.0.1-12.module_el8.6.0+2781+fed64c13
- python2-bson Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-chardet Fixed in 3.0.4-10.module_el8.6.0+2781+fed64c13
- python2-coverage Fixed in 4.5.1-4.module_el8.6.0+2781+fed64c13
- python2-dns Fixed in 1.15.0-10.module_el8.6.0+2781+fed64c13
- python2-docs Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docs-info Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docutils Fixed in 0.14-12.module_el8.6.0+2781+fed64c13
- python2-funcsigs Fixed in 1.0.2-13.module_el8.6.0+2781+fed64c13
- python2-idna Fixed in 2.5-7.module_el8.6.0+2781+fed64c13
- python2-ipaddress Fixed in 1.0.18-6.module_el8.6.0+2781+fed64c13
- python2-jinja2 Fixed in 2.10-9.module_el8.6.0+2781+fed64c13
- python2-markupsafe Fixed in 0.23-19.module_el8.6.0+2781+fed64c13
- python2-mock Fixed in 2.0.0-13.module_el8.6.0+2781+fed64c13
- python2-nose Fixed in 1.3.7-31.module_el8.6.0+2781+fed64c13
- python2-numpy Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-doc Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-f2py Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-pluggy Fixed in 0.6.0-8.module_el8.6.0+2781+fed64c13
- python2-psycopg2 Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-debug Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-tests Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-py Fixed in 1.5.3-6.module_el8.6.0+2781+fed64c13
- python2-pygments Fixed in 2.2.0-22.module_el8.6.0+2781+fed64c13
- python2-pymongo Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-pymongo-gridfs Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-pysocks Fixed in 1.6.8-6.module_el8.6.0+2781+fed64c13
- python2-pytest Fixed in 3.4.2-13.module_el8.6.0+2781+fed64c13
- python2-pytest-mock Fixed in 1.9.0-4.module_el8.6.0+2781+fed64c13
36 further packages in CloudLinux 8 not shown (first 40 listed).
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- mediawiki Fixed in 1:1.35.2-1
- pygments Fixed in 2.7.1+dfsg-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- mediawiki Fixed in 1:1.35.2-1
- pygments Fixed in 2.7.1+dfsg-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- mediawiki Fixed in 1:1.35.2-1
- pygments Fixed in 2.7.1+dfsg-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- pygments Fixed in 2.1+dfsg-1ubuntu0.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- pygments Fixed in 2.2.0+dfsg-1ubuntu0.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- pygments Fixed in 2.3.1+dfsg-1ubuntu2.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- pygments Fixed in 1.6+dfsg-1ubuntu1.1+esm1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.