Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce63
- https://github.com/crossbario/autobahn-python/pull/1916
- https://github.com/crossbario/autobahn-python/releases/tag/v26_7_1
- https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3
FAQ
What is CVE-2026-77528?
CVE-2026-77528 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 maxMessagePayloadSi...
How severe is CVE-2026-77528?
CVE-2026-77528 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-77528?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.