What’s Vulnerable › Vulnerabilities

CVE-2026-54274: AIOHTTP: Incomplete websocket frame payloads bypass memory limits

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-22 · updated 2026-10-25
• Weakness: CWE-770

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, if an attacker sends large incomplete websocket frame payloads, it may be possible to bypass the usual size limits on memory use. This vulnerability is fixed in 3.14.1.

Affected products

• aio-libs aiohttp: before 3.14.1 — fixed in 3.14.1
• Pypi Aiohttp: before 3.14.1; 0.1, 0.10.0, 0.10.1, 0.10.2, 0.11.0, 0.12.0 (+301) — fixed in 3.14.1

How to fix

Upgrade to a fixed version: aio-libs aiohttp 3.14.1; Pypi Aiohttp 3.14.1. Check the vendor advisory for mitigations.

References

• https://github.com/aio-libs/aiohttp/commit/14b6ee851fb16ec199acb950de0c82d476799e7d
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xcgm-r5h9-7989

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