Medium severity · published Sep 18, 2026
CVE-2026-54147
http4k: `DigestAuthProvider.verify` ignored configured algorithm and did not bind to request URI
6.5
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HT
http4k · http4k
< 4.51.0.0; >= 5.0.0.0, < 5.42.0.0; >= 6.0.0.0, < 6.50.0.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54147
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54147
github.com
https://github.com/http4k/http4k/commit/65d23d99fc5afbe34f29d8f61d0a003fbebb381c
github.com
https://github.com/http4k/http4k/releases/tag/6.50.0.0
github.com
https://github.com/http4k/http4k/security/advisories/GHSA-vxxm-wwqh-mh47
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