Cyber Resilience

CVE-2026-67289

Public PoC
Published
01 August 2026
Modified
05 August 2026
CVSS Score v4 9.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0038 31th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-67289 is a critical-severity HTTP Request/Response Splitting (CWE-113) vulnerability. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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)

A05:2025 Injection

EU & UK References

Vulnerability Data

FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's ServerHostname and, when the client connects through an HTTP proxy, is written…

more

directly into the proxy CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary headers/requests into the HTTP proxy CONNECT request.

CWE(s)
CWE-113

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-40927Shared CWE-113
CVE-2025-71381Shared CWE-113
CVE-2025-61689Shared CWE-113
CVE-2025-41234Shared CWE-113
CVE-2023-0508Shared CWE-113
CVE-2025-0825Shared CWE-113
CVE-2024-52875Shared CWE-113
CVE-2026-38967Shared CWE-113
CVE-2025-62826Shared CWE-113
CVE-2025-55271Shared CWE-113

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.4.2
  • V4.1.3
  • V1.3.6
  • V4.2.3

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation stops unneutralized CR/LF characters from being accepted and later emitted in HTTP headers.

SI-15 Information Output Filtering good match

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.

PR.PS-06 mostly match
prevents

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect CRLF injection flaws before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection into HTTP headers.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for controls against injection flaws including HTTP header manipulation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the likelihood of header-splitting vulnerabilities through proper component isolation.

A.8.28 Secure coding partial match
prevents

Secure coding standards require neutralization of CRLF sequences before inclusion in HTTP headers.

A.8.15 Logging none match
none

Logging of HTTP traffic can record header-splitting attempts, aiding detection and forensics.

References