Cyber Resilience

CVE-2023-25950

Haproxy 2.6.1 – 2.6.7

Published
11 April 2023
Modified
11 February 2025
Patch / advisory
CVSS Score v3.1 7.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.029 86th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2023-25950 is a high-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Haproxy Haproxy. Its CVSS base score is 7.3 (High).

Operationally, ranked in the top 14% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

HTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7 allows a remote attacker to alter a legitimate user's request. As a result, the attacker may obtain sensitive information or cause a denial-of-service (DoS) condition.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-40225Same product: Haproxy Haproxy
CVE-2026-55203Same product: Haproxy Haproxy
CVE-2023-45539Same product: Haproxy Haproxy
CVE-2026-33555Same product: Haproxy Haproxy
CVE-2024-45506Same product: Haproxy Haproxy
CVE-2023-0836Same product: Haproxy Haproxy
CVE-2026-55204Same product: Haproxy Haproxy
CVE-2023-25725Same product: Haproxy Haproxy
CVE-2025-11230Same product: Haproxy Haproxy
CVE-2023-33193Shared CWE-444

Affected Assets

haproxy
haproxy
2.7.0 · 2.6.1 — 2.6.7

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)
  • V4.1.3
  • V4.2.4
  • V1.5.3
  • V4.1.1

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-01 mostly match
prevents

Configuration management can enforce uniform HTTP parsing rules across intermediaries, directly mitigating inconsistent interpretation.

DE.CM-01 partial match
prevents

Network monitoring can detect smuggling attempts via anomalous HTTP traffic or logs, while eliminating the inconsistency directly aids detection of such events.

PR.IR-01 partial match
prevents

Network protections can enforce consistent HTTP proxy/firewall behavior to block smuggling, and removing the weakness helps prevent unauthorized access via request smuggling.

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.

detects

Security testing can detect HTTP request smuggling vulnerabilities in intermediary components.

degrades

Network security controls can enforce consistent HTTP parsing and proxy behavior that mitigates request smuggling.

degrades

Secure network services include hardening proxies and gateways against inconsistent HTTP interpretation.

prevents

Secure SDLC practices require threat modeling and testing for HTTP parsing inconsistencies in intermediaries.

prevents

Application security requirements can mandate strict HTTP message validation and canonicalization.

prevents

Secure architecture principles include consistent protocol handling and defense-in-depth for proxies.

References