All vulnerabilities
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 acr

HAProxy Data Plane API EE
CVSS
9.8Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published12 Oct 2026Updated 13 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

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.

Text from CVE List

Affected versions 10

  • Data Plane API EEaffected: 2.2.0-ee1 through 2.9.28-ee1CVE List
  • Data Plane API EEaffected: 3.0-ee through 3.0.24-ee1CVE List
  • Data Plane API EEaffected: 3.1-ee through 3.2.16-ee1CVE List
  • Data Plane API EEaffected: 3.3-ee through 3.3.8-ee1CVE List
  • Data Plane API EEaffected: 3.4-ee through 3.4.3-ee2CVE List
  • Data Plane API CEaffected: 2.2.0 through 2.9.28CVE List
  • Data Plane API CEaffected: 3.0.0 through 3.0.24CVE List
  • Data Plane API CEaffected: 3.1.0 through 3.2.16CVE List
  • Data Plane API CEaffected: 3.3.0 through 3.3.8CVE List
  • Data Plane API CEaffected: 3.4.0 through 3.4.3CVE List

References 4