---
id: GHSA-c7jm-38gq-h67h
title: >-
  http4k: `ServerFilters.DigestAuth` / `DigestAuthProvider` defaulted to an
  always-true nonce verifier, disabling replay protection in default deployments
summary: >-
  http4k: `ServerFilters.DigestAuth` / `DigestAuthProvider` defaulted to an
  always-true nonce verifier, disabling replay protection in default deployments
severity: medium
cwe:
  - CWE-294
vendor: http4k
product: 'org.http4k:http4k-security-digest'
ecosystem: maven
affected:
  - 'org.http4k:http4k-security-digest >= 6.0.0.0, < 6.48.0.0'
  - 'org.http4k:http4k-security-digest >= 5.0.0.0, < 5.42.0.0'
  - 'org.http4k:http4k-security-digest < 4.51.0.0'
patched:
  - 'org.http4k:http4k-security-digest 6.48.0.0'
  - 'org.http4k:http4k-security-digest 5.42.0.0'
  - 'org.http4k:http4k-security-digest 4.51.0.0'
published: '2026-06-19'
updated: '2026-06-19'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-c7jm-38gq-h67h'
references:
  - url: 'https://github.com/http4k/http4k/security/advisories/GHSA-c7jm-38gq-h67h'
  - url: 'https://github.com/http4k/http4k/commit/4f904b4692'
  - url: 'https://github.com/http4k/http4k/commit/8a52b615b1'
  - url: 'https://datatracker.ietf.org/doc/html/rfc7616#section-3.4'
  - url: 'https://github.com/http4k/http4k/releases/tag/6.48.0.0'
  - url: 'https://github.com/advisories/GHSA-c7jm-38gq-h67h'
tags:
  - ghsa
  - maven
ingestedAt: '2026-06-22T13:35:24.319Z'
---

## Overview

### Impact

`ServerFilters.DigestAuth` and the underlying `DigestAuthProvider` both defaulted their `nonceVerifier` parameter to `{ true }` — i.e. every nonce was accepted regardless of value, age, or prior use. Any deployment using the default configuration had **no replay protection** on Digest authentication; a captured `Authorization: Digest …` response could be replayed indefinitely against the same protected resource.

The nonce-verification mechanism in Digest auth is the primary anti-replay control — without it, Digest reduces to a credential bound only to a stale nonce string.

**Who is affected:** any application using `ServerFilters.DigestAuth` or `DigestAuthProvider` with the default `nonceVerifier`. The broken default has been present since `DigestAuthProvider` was introduced (2021). Exploitation requires the attacker to first capture a valid Digest response (network observation, log access, etc.) — non-trivial in modern TLS deployments but not impossible. Anyone running Digest auth with default config should treat upgrade as urgent.

### Patches

| Line | Fixed in | Edition |
|------|----------|---------|
| v6.x (Community) | **6.48.0.0** | Community |
| v5.x (LTS) | **5.42.0.0** | Enterprise — contact [enterprise@http4k.org](mailto:enterprise@http4k.org) (if Digest auth is present in your v5.x line) |
| v4.x (LTS) | **4.51.0.0** | Enterprise — contact [enterprise@http4k.org](mailto:enterprise@http4k.org) (if Digest auth is present in your v4.x line) |

The fix (`[Break]`) removes the default value for `nonceVerifier` from both `ServerFilters.DigestAuth` and `DigestAuthProvider`. Callers must now supply a real verifier explicitly — the broken default cannot be silently inherited.

### Workarounds

For deployments that cannot upgrade immediately: explicitly supply a `nonceVerifier` that tracks issued nonces, enforces a TTL, and rejects re-use. Do not rely on the default.

## Affected packages

- `org.http4k:http4k-security-digest >= 6.0.0.0, < 6.48.0.0`
- `org.http4k:http4k-security-digest >= 5.0.0.0, < 5.42.0.0`
- `org.http4k:http4k-security-digest < 4.51.0.0`

## Remediation

Upgrade to a patched release:

- `org.http4k:http4k-security-digest 6.48.0.0`
- `org.http4k:http4k-security-digest 5.42.0.0`
- `org.http4k:http4k-security-digest 4.51.0.0`