CVE-2026-116579: crossbario autobahn-python · Data Amplification
Affects crossbario autobahn-pythonSource CVE Database V5
Not known to be exploited · CVSS 5.9 Medium : upgrade to 26.10.1 when convenient.
Data as of 26 Oct 2026, 20:58 UTC
- Patch
- Available – fixed in 26.10.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade crossbario autobahn-python to 26.10.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| crossbarioautobahn-python | Affected
| Fixed in
|
Description
Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. From 26.7.1 until 26.10.1, PerMessageBrotli.decompress_message_data in compress_brotli.py calls the Brotli decompressor without an output limit and checks maxMessagePayloadSize only after a complete frame has been inflated. An unauthenticated WebSocket client can send a small, highly compressed frame that allocates hundreds of MiB before rejection, causing memory-exhaustion denial of service on servers that enable the opt-in permessage-brotli feature through the compress extra. Deflate and bzip2 already enforce the remaining output budget and are outside this residual vulnerability. This issue is fixed in version 26.10.1.
References
- github.com/crossbario/autobahn-python/security/advisories/GHSA-pjh6-c8mg-3x7m (opens in a new tab)
- github.com/crossbario/autobahn-python/pull/1987 (opens in a new tab)
- github.com/crossbario/autobahn-python/commit/a41442bbee4f6126a8ce1bb892840124c24d16f1 (opens in a new tab)
- github.com/crossbario/autobahn-python/releases/tag/v26_10_1 (opens in a new tab)