Vulnerability · Published Sep 27, 2026 · Assigned by VulnCheck

CVE-2026-100834http4k before 6.48.0.0 Digest Authentication Replay Protection Bypass

Medium 5.9

In plain English

A medium-severity security flaw in http4k from http4k. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.3%top 74.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Maven	org.http4k:http4k-security-digest	6.48.0.0	GHSA-c7jm-38gq-h67h
Maven	org.http4k:http4k-security-digest	5.42.0.0	GHSA-c7jm-38gq-h67h
Maven	org.http4k:http4k-security-digest	4.51.0.0	GHSA-c7jm-38gq-h67h

Affected products (as reported)

Vendor	Product	Versions
http4k	http4k	6.0.0.0 – before 6.48.0.0
http4k	http4k	5.0.0.0 – before 5.42.0.0
http4k	http4k	0 – before 4.51.0.0

Weakness: CWE-294 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-c7jm-38gq-h67h) vendor-advisory
Patch Commit patch
Patch Commit patch
VulnCheck Advisory: http4k before 6.48.0.0 Digest Authentication Replay Protection Bypass third-party-advisory