Is there a public exploit for CVE-2026-128124?

No public exploit for CVE-2026-128124 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-128124?

CVE-2026-128124 scores CVSS 8.2 (v4.0), rated high.

What does CVE-2026-128124 affect?

CVE-2026-128124 affects aio-libs aiohttp.

8.2 High

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python.

CVE-2026-128124

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Application.adddomain() 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.

Assessment

CVSS: 8.2 (v4.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 13 November 2026
Last updated: 13 November 2026
Affected: aio-libs · aiohttp
Assigner: GitHub_M

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

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