SB20260831104 - Fedora 44 update for python-linkify-it-py
Published: August 31, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Inefficient regular expression complexity (CVE-ID: CVE-2026-48801)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in LinkifyIt.prototype.match when processing user-supplied text containing many fuzzy links or email-like strings. A remote attacker can send a specially crafted request body to cause a denial of service.
This affects services that synchronously render untrusted Markdown with linkification enabled on the request path, including transitive use through markdown-it with linkify:true.
2) Inefficient Algorithmic Complexity (CVE-ID: CVE-2026-59887)
CWE-ID: CWE-407 - Inefficient Algorithmic Complexity
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in the mailto: schema validator scan loop when processing user-supplied text containing repeated mailto: sequences. A remote attacker can send specially crafted input to cause a denial of service.
The issue is reachable through the documented .test() and .match() API and through markdown rendering with linkification enabled.
Remediation
Install update from vendor's website.