CVE-2026-100834: HTTP4K

Medium severity, CVSS 5.9. EPSS: 0.3% chance of exploitation in the next 30 days.

http4k's Digest authentication module (org.http4k:http4k-security-digest) before versions 6.48.0.0, 5.42.0.0 and 4.51.0.0 defaults the nonceVerifier parameter of ServerFilters.DigestAuth and DigestAuthProvider to { true }, so every nonce is accepted regardless of its value, age, or prior use. Applications relying on this default have no replay protection on Digest authentication: an attacker who can capture a valid 'Authorization: Digest' response (for example by observing network traffic or reading logs) can replay it indefinitely against the same protected resource.

Affected products

• HTTP4K HTTP4K: before 6.48.0.0 (fixed in 6.48.0.0); before 5.42.0.0 (fixed in 5.42.0.0); before 4.51.0.0 (fixed in 4.51.0.0)

Published 2026-09-27. Last modified 2026-09-30.