CVE-2026-54148: HTTP4K

High severity, CVSS 8.1. EPSS: 0.6% chance of exploitation in the next 30 days.

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest does not compare the uri parameter in an Authorization: Digest response with the actual request URL. An attacker who captures a valid Digest authentication response can replay it against another URL served by the same realm, bypassing the per-request-URI binding and potentially gaining unauthorized read or write access. This issue is fixed in versions 4.51.0.0, 5.42.0.0, and 6.50.0.0.

Affected products

• HTTP4K HTTP4K: before 4.51.0.0 (fixed in 4.51.0.0); from 5.0.0.0, before 5.42.0.0 (fixed in 5.42.0.0); from 6.0.0.0, before 6.50.0.0 (fixed in 6.50.0.0)

Published 2026-09-18. Last modified 2026-09-24.