Vulnerability in Pygments
CVE-2021-27291
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…
Vulnerability class: ReDoS (Regular Expression Denial of Service)
EPSS: 0.038 (88.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Pygments
- Debian Debian_linux — versions 9.0, 10.0
- Fedoraproject Fedora — versions 32, 33
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-27291?
- CVE-2021-27291 is a high-severity vulnerability in Pygments, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2021-03-17.
- How severe is CVE-2021-27291?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-27291 known to be exploited?
- 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.