CVE-2026-109575

In HAProxy Data Plane API 2.2.0 through 3.4.3 (and corresponding Enterprise Edition releases), Server.ConfigureAPI() has process-global authentication logic that improperly drops security controls across multiple transport types. When a TLS Certificate Authority (tls_ca) is configured and a numeric TLS port (tls_port) is specified, the application globally disables Basic authentication on its shared internal request handler. Because this handler is shared concurrently among HTTP, HTTPS, and UNIX domain socket listeners, and mutual TLS (mTLS) client certificate verification (tls.RequireAndVerifyClientCert) is enforced exclusively on the HTTPS server path, all other simultaneously active non-mTLS listeners fail open. Consequently, an unauthenticated attacker capable of reaching an affected HTTP or UNIX management endpoint can completely bypass credentials to gain full API administrative access. This allows unauthorized remote or local actors to read sensitive, cleartext HAProxy configuration data or replace the managed configuration entirely via the raw configuration endpoint. This has been fixed in versions 3.4.4, 3.3.9, 3.2.17, 3.0.25, 2.9.29, and their respective EE backports by migrating to a per-request TLS connection-state validation model.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/haproxytech/dataplaneapi/commit/c3ae4e3ccff5490d44650565e445c4b15e8aff8c
https://github.com/haproxytech/dataplaneapi/releases/tag/v3.4.4
https://www.haproxy.com/documentation/haproxy-data-plane-api/
https://www.haproxy.com/documentation/haproxy-data-plane-api/community/changelog/#version-3.4

Configurations

No configuration.

History

12 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-12 20:17

Updated : 2026-10-16 19:55

NVD link : CVE-2026-109575

Mitre link : CVE-2026-109575

CVE.ORG link : CVE-2026-109575

JSON object : View

Products Affected

No product.

CWE

CWE-306

Missing Authentication for Critical Function

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