Vulnerability · Published Mar 3, 2021 · Assigned by mitre
CVE-2021-26813
High 7.5
In plain English
A high-severity security flaw in the python-markdown2 package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.3% (higher than 84% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.5High
Exploit odds (30 days)2.3%top 16.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | python-markdown2 | 2.3.10-1.1 | DEBIAN-CVE-2021-26813 |
| Debian:13 | python-markdown2 | 2.3.10-1.1 | DEBIAN-CVE-2021-26813 |
| Debian:14 | python-markdown2 | 2.3.10-1.1 | DEBIAN-CVE-2021-26813 |
| PyPI | markdown2 | 2.4.0 | GHSA-jr9p-r423-9m2r |
| PyPI | markdown2 | 2.4.0 | PYSEC-2021-20 |
| Ubuntu:22.04:LTS | python-markdown2 | no fix listed | UBUNTU-CVE-2021-26813 |
| Ubuntu:24.04:LTS | python-markdown2 | no fix listed | UBUNTU-CVE-2021-26813 |
| Ubuntu:25.10 | python-markdown2 | no fix listed | UBUNTU-CVE-2021-26813 |
| Ubuntu:26.04:LTS | python-markdown2 | no fix listed | UBUNTU-CVE-2021-26813 |
| Ubuntu:26.10 | python-markdown2 | no fix listed | UBUNTU-CVE-2021-26813 |
Affected products (as reported)
References
- https://github.com/trentm/python-markdown2/pull/387 x_refsource_MISC
- FEDORA-2021-77191478ad vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-0337384e41 vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-e235a0da4a vendor-advisory, x_refsource_FEDORA