CVE-2026-77528

Name	CVE-2026-77528
Description	Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. Prior to 26.7.1, WebSocket endpoints that accept permessage-deflate and rely on maxMessagePayloadSize enforce that limit against the compressed frame length before inflation but do not recheck the decompressed message size before delivery. A remote unauthenticated client can send a valid compressed frame below the configured wire-size limit that expands beyond the application message limit, causing oversized data to be allocated, joined, validated, and passed to application callbacks. This can create resource-exhaustion pressure, but the advisory does not establish confidentiality or integrity impact. This issue is fixed in version 26.7.1.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-autobahn (PTS)	bookworm	22.7.1+dfsg1-2	vulnerable
	trixie	23.1.2+dfsg1-2	vulnerable
	forky, sid	24.4.2+dfsg1-5	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-autobahn	source	(unstable)	(unfixed)

Notes

https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3-p566
https://github.com/crossbario/autobahn-python/pull/1916
Fixed by: https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce6344e056970e613 (v26.7.1)