CVE-2026-128124

AIOHTTP: Event loop stall in add_domain() wildcard matching

Published Nov 13, 2026 CVSS 4.0 · 8.2 High EPSS n/a KEV · Not listed
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Application.add_domain() converts every asterisk wildcard in a domain mask into a greedy regular-expression fragment, so a mask containing two or more wildcards can take polynomial time to reject a long Host header that does not match. A remote attacker can repeatedly send such headers to a server configured with a multi-wildcard domain mask and stall the event loop. This issue is fixed in version 3.14.4.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Description AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Application.add_domain() converts every asterisk wildcard in a domain mask into a greedy regular-expression fragment, so a mask containing two or more wildcards can take polynomial time to reject a long Host header that does not match. A remote attacker can repeatedly send such headers to a server configured with a multi-wildcard domain mask and stall the event loop. This issue is fixed in version 3.14.4.
Title AIOHTTP: Event loop stall in add_domain() wildcard matching
Weaknesses CWE-1333
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

No data.

Weaknesses
  • CWE-1333

    Inefficient Regular Expression Complexity

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 13, 2026, 8:22 PM
Reserved
Nov 12, 2026, 10:42 PM
Status
Received
Published
Nov 13, 2026, 9:17 PM
Modified
Nov 13, 2026, 9:17 PM