Vulnerability in Http4k
CVE-2026-100834
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.
Published .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/http4k/http4k/security/advisories/GHSA-c7jm-38gq-h67h (vendor-advisory)
- github.com/http4k/http4k/commit/8a52b615b1 (patch)
- github.com/http4k/http4k/commit/4f904b4692 (patch)
- www.vulncheck.com/advisories/http4k-before-6.48.0.0-digest-authentication-repla… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100834?
- CVE-2026-100834 is a medium-severity vulnerability in Http4k, classified under Authentication Bypass by Capture-replay. CVSS score: 5.9/10. Published 2026-09-27.
- How severe is CVE-2026-100834?
- Medium severity. CVSS v3 base score is 5.9 out of 10.