CVE•Published 2026-07-08•Modified 2026-07-09•0 articles on news•5 live references•NVD data

CVE-2026-59922Mistune_project · Mistune

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

—

Weaknesses (CWE)

CWE-407Inefficient Algorithmic Complexity CWE-1333Inefficient Regular Expression Complexity

Description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

Timeline

Published 2026-07-08

Modified 2026-07-09

External references

NVD MITRE Exploit-DB trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common). Live host counts are a Premium feature.

Shodan · vuln tag

vuln:CVE-2026-59922

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Mistune Project Mistune"

All exposed Mistune Project Mistune instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Mistune"

HTTP body or banner mentions "Mistune" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-59922