GHSA-pjh6-c8mg-3x7m: autobahn (CVE-2026-116579)

Package	Ecosystem	Affected	Fixed in
autobahn	PyPI	>=26.7.1, <26.10.1	26.10.1

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Autobahn Python versions 26.7.1 up to but not including 26.10.1 are affected through the permessage-brotli extension, which inflates each received frame in full before checking the configured maxMessagePayloadSize limit. An unauthenticated WebSocket client can send a tiny brotli-compressed frame and make a server that has enabled permessage-brotli allocate hundreds of megabytes, exhausting memory. The fix is to upgrade autobahn to version 26.10.1.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.9	Medium	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0043, the 36th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:07 UTC First seen by agentprime
31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.