CVE-2026-85077

Sanic: HTTP response header injection via missing CR/LF validation in Sanic HTTP/1.1 responses

Published Sep 17, 2026 CVSS 3.1 · 8.2 High EPSS < 1% KEV · Not listed
Description
Sanic is an opensource python web server/framework. Prior to version 24.12.1, and in version 25.12.0, the HTTP/1.1 response pipeline in sanic/response/types.py serializes response header names and values without rejecting carriage-return or line-feed characters. Applications that place attacker-controlled data in response.headers, file(..., filename=...), or cookie path and domain attributes can therefore emit injected headers and may split responses. Depending on application and proxy behavior, this can enable session fixation through injected cookies, cache poisoning, or security-header corruption. This issue is fixed in versions 24.12.1 and 25.12.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Sanic-org
Sanic-org sanic
Vendors & Products Sanic-org
Sanic-org sanic
Type Values Removed Values Added
Description Sanic is an opensource python web server/framework. Prior to version 24.12.1, and in version 25.12.0, the HTTP/1.1 response pipeline in sanic/response/types.py serializes response header names and values without rejecting carriage-return or line-feed characters. Applications that place attacker-controlled data in response.headers, file(..., filename=...), or cookie path and domain attributes can therefore emit injected headers and may split responses. Depending on application and proxy behavior, this can enable session fixation through injected cookies, cache poisoning, or security-header corruption. This issue is fixed in versions 24.12.1 and 25.12.1.
Title Sanic: HTTP response header injection via missing CR/LF validation in Sanic HTTP/1.1 responses
Weaknesses CWE-113
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 21, 2026, 8:45 PM
Reserved
Sep 2, 2026, 9:21 PM
Status
Awaiting Analysis
Published
Sep 17, 2026, 3:16 PM
Modified
Sep 24, 2026, 9:22 PM
Severity
Important
Public date
Sep 17, 2026, 2:26 PM