CVE-2026-85078
Published:September 17, 2026
Updated:September 22, 2026
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.
Affected Packages
sanic (CONDA):
Affected version(s) =25.3.0 <25.12.1Fix Suggestion:
Update to version 25.12.1https://github.com/sanic-org/sanic.git (GITHUB):
Affected version(s) >=v25.3.0 <v25.12.1Fix Suggestion:
Update to version v25.12.1https://github.com/sanic-org/sanic.git (GITHUB):
Affected version(s) >=v21.9.0 <v24.12.1Fix Suggestion:
Update to version v24.12.1sanic (PYTHON):
Affected version(s) >=25.3.0 <25.12.1Fix Suggestion:
Update to version 25.12.1sanic (PYTHON):
Affected version(s) >=21.9.0 <24.12.1Fix Suggestion:
Update to version 24.12.1Related Resources (9)
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Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
LOW
Weakness Type (CWE)
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')