CVE-2026-54147

What it is

http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.50.0.0, DigestAuthProvider.verify in http4k-security-digest ignores its configured algorithm parameter and verifies every Digest response with hardcoded MD5. Deployments configured for SHA-256 therefore receive weaker MD5-based verification, exposing Digest authentication to collision-related attack paths that depend on the hash function's collision resistance. This issue is fixed in versions 4.51.0.0, 5.42.0.0, and 6.50.0.0.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-18 16:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-24 21:25 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 6.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-18 16:17 UTC

Last modified

2026-09-24 21:25 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-327 · Broken cryptographic algorithm

Record status

Deferred

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-54147.md and follow it. Check whether this project is affected by CVE-2026-54147. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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