High severity7.5NVD Advisory· Published Mar 3, 2021· Updated Jun 17, 2026
CVE-2021-26813
CVE-2021-26813
Description
markdown2 >=1.0.1.18, fixed in 2.4.0, is affected by a regular expression denial of service vulnerability. If an attacker provides a malicious string, it can make markdown2 processing difficult or delayed for an extended period of time.
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Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
markdown2PyPI | >= 1.0.1.18, < 2.4.0 | 2.4.0 |
Affected products
9- markdown2/markdown2description
- osv-coords4 versionspkg:rpm/opensuse/python-markdown2&distro=openSUSE%20Tumbleweedpkg:pypi/markdown2pkg:rpm/opensuse/python-markdown2&distro=openSUSE%20Leap%2015.2pkg:rpm/suse/python-markdown2&distro=SUSE%20Package%20Hub%2015%20SP2
< 2.4.0-2.4+ 3 more
- (no CPE)range: < 2.4.0-2.4
- (no CPE)range: >= 1.0.1.18, < 2.4.0
- (no CPE)range: < 2.4.0-lp152.2.3.1
- (no CPE)range: < 2.4.0-bp152.2.4.1
- cpe:2.3:a:markdown2_project:markdown2:*:*:*:*:*:*:*:*Range: >=1.0.1.18,<2.4.0
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*+ 2 more
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
Patches
Vulnerability mechanics
References
11- github.com/trentm/python-markdown2/pull/387nvdExploitThird Party AdvisoryWEB
- github.com/advisories/GHSA-jr9p-r423-9m2rghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2021-26813ghsaADVISORY
- github.com/pypa/advisory-database/tree/main/vulns/markdown2/PYSEC-2021-20.yamlghsaWEB
- github.com/trentm/python-markdown2/commit/7b651260739647de5198323e0445b1618750c374ghsaWEB
- lists.fedoraproject.org/archives/list/[email protected]/message/BRP5RN35JZTSJ3JT4722F447ZDK7LZS5ghsaWEB
- lists.fedoraproject.org/archives/list/[email protected]/message/J752422YELXLMLZJPVJVKD2KKHHQRVEHghsaWEB
- lists.fedoraproject.org/archives/list/[email protected]/message/JTIX5UXRDJZJ57DO4V33ZNJTNKWGBQLYghsaWEB
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRP5RN35JZTSJ3JT4722F447ZDK7LZS5/nvd
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J752422YELXLMLZJPVJVKD2KKHHQRVEH/nvd
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JTIX5UXRDJZJ57DO4V33ZNJTNKWGBQLY/nvd
News mentions
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