CVE-2026-85077
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-85077 is a high-severity HTTP Request/Response Splitting (CWE-113) vulnerability. Its CVSS base score is 8.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-81626
Vulnerability Data
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,…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.4.2V4.1.3V1.3.6V4.2.3
Mitigating Controls (NIST 800-53 r5) AI
Input validation stops unneutralized CR/LF characters from being accepted and later emitted in HTTP headers.
Output filtering can neutralize CRLF sequences before they reach HTTP response headers.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input sanitization and header handling that prevent CRLF injection.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection into HTTP headers.
Application security requirements explicitly call for controls against injection flaws including HTTP header manipulation.
Secure architecture principles reduce the likelihood of header-splitting vulnerabilities through proper component isolation.
Secure coding standards require neutralization of CRLF sequences before inclusion in HTTP headers.
Security testing in development and acceptance can detect CRLF injection flaws before deployment.