CVE-2026-85078
sanic chunked trailer request smuggling allows hidden second request execution
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
Sanic is an opensource python web server/framework. In version 25.12.0, Sanic's core HTTP/1.1 chunked-body handling does not fully consume the trailer-part after the terminating zero chunk before reusing the keep-alive connection buffer. A remote unauthenticated client can place attacker-controlled bytes in that trailer region, causing Sanic to parse and route them as a hidden second request after the outer request. This breaks HTTP request-boundary integrity and can provide a request-smuggling primitive when Sanic is deployed behind intermediaries. This issue is fixed in version 25.12.1.
| CWE | CWE-444 |
| Vendor | sanic-org |
| Product | sanic |
| Published | Sep 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low
Affected Versions
sanic-org / sanic
< 24.12.1 >= 25.12.0, < 25.12.1
References
github.com: https://github.com/sanic-org/sanic/security/advisories/GHSA-wmj6-g64g-j7q5 github.com: https://github.com/sanic-org/sanic/pull/3164 github.com: https://github.com/sanic-org/sanic/pull/3165 github.com: https://github.com/sanic-org/sanic/commit/47349d689d65fa1907977ac100e867894aeafb22 github.com: https://github.com/sanic-org/sanic/commit/69a10d3b06babaa9e5f6d1af577364e9e53b6dea github.com: https://github.com/sanic-org/sanic/commit/a332796506c7c588b6930b02a8886e43eb8ea8d6 github.com: https://github.com/sanic-org/sanic/releases/tag/v24.12.1 github.com: https://github.com/sanic-org/sanic/releases/tag/v25.12.1