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MEDIUM severity

CVE-2026-54147

MEDIUMFix: http4k/http4k@65d23d9

CVE-2026-54147 is a medium-severity (CVSS 6.5) vulnerability in org.http4k:http4k-security-digest. O3 Security confirms whether CVE-2026-54147 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI

Published
Aug 17, 2026
Updated
Aug 17, 2026
Affected
3 pkgs
Patched
2 / 3
Exploits
None indexed
Exploitation data as of Aug 17, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

3 pkgs affected
org.http4k:http4k-security-digestorg.http4k:http4k-security-digestorg.http4k:http4k-security-digest

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

An issue in DigestAuthProvider.verify:

Algorithm silently forced to MD5. The configured algorithm parameter was ignored — every verification used MD5 regardless of configuration. Deployments believing they were running SHA-256 Digest auth were silently inheriting MD5's collision weaknesses, including documented attack paths against Digest schemes that rely on the hash being collision-resistant.

Who is affected: any application using http4k-security-digest for HTTP Digest authentication. The bug has been present since DigestAuthProvider was introduced (commit 8a52b615b1, 2021).

Patches

LineFixed inEdition
v6.x (Community)6.50.0.0Community
v5.x (LTS)5.42.0.0Enterprise — contact [email protected] (if Digest auth is present in your v5.x line)
v4.x (LTS)4.51.0.0Enterprise — contact [email protected] (if Digest auth is present in your v4.x line)

The fix:

  • Hashes with the configured algorithm instead of hardcoded MD5.

Workarounds

For deployments that cannot upgrade immediately:

  • Algorithm gap: do not rely on algorithm configuration; assume MD5 is in use and treat the Digest credentials as low-trust.

References

Affected Packages

3 total 2 fixed
EcosystemPackageVulnerable rangeFix
Mavenorg.http4k:http4k-security-digest6.0.0.0&&< 6.50.0.06.50.0.0
Mavenorg.http4k:http4k-security-digest5.0.0.0&&< 5.42.0.05.42.0.0
Mavenorg.http4k:http4k-security-digestall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.http4k:http4k-security-digest. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update org.http4k:http4k-security-digest to 6.50.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54147 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2026-54147 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-54147. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact An issue in `DigestAuthProvider.verify`: **Algorithm silently forced to MD5.** The configured `algorithm` parameter was ignored — every verification used MD5 regardless of configuration. Deployments believing they were running SHA-256 Digest auth were silently inheriting MD5's collision weaknesses, including documented attack paths against Digest schemes that rely on the hash being collision-resistant. **Who is affected:** any application using `http4k-security-digest` for HTTP Digest authentication. The bug has been present since `DigestAuthProvider` was introduced (commit `8a5
O3 Security · Impact-Aware SCA

Is CVE-2026-54147 in your dependencies?

O3 detects CVE-2026-54147 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.