aio-libs/aiohttp · Security
AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
- GHSA ID
- GHSA-mq44-7p77-q5h7
- CVE ID
- CVE-2026-59881
- Severity
- medium
- Published
- Updated
- CVSS v4
- 6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Description
Summary
The client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated.
Impact
A client may unexpectedly decompress WebSocket frames when explicitly opted out. This could lead to additional CPU/memory consumption, but is unlikely to be a significant issue unless a zip bomb vulnerability or similar is also present.
Patch: https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6
CWEs
- CWE-20 · Improper Input Validation
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7 ↗
- https://nvd.nist.gov/vuln/detail/CVE-2026-59881 ↗
- https://github.com/aio-libs/aiohttp/pull/12978 ↗
- https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6 ↗
- http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2 ↗
- https://github.com/advisories/GHSA-mq44-7p77-q5h7 ↗