What is CVE-2026-33079?

CVE-2026-33079 is a high-severity vulnerability in Lepture Mistune, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2026-05-06.

How severe is CVE-2026-33079?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Lepture Mistune

CVE-2026-33079

In versions 3.0.0a1 through 3.2.0 of Mistune, there is a ReDoS (Regular Expression Denial of Service) vulnerability in `LINK_TITLE_RE` that allows an attacker who can supply Markdown for parsing to cause denial of service. The regular expr…

Vulnerability class: ReDoS (Regular Expression Denial of Service)

EPSS: 0.005 (38.4th 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

Lepture Mistune — versions >=3.0.0a1, <= 3.2.0

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
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Frequently asked questions

What is CVE-2026-33079?: CVE-2026-33079 is a high-severity vulnerability in Lepture Mistune, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2026-05-06.
How severe is CVE-2026-33079?: High severity. CVSS v3 base score is 7.5 out of 10.