NetSight
medium5.9

CVE-2026-69206

Http4s: DigestAuth allows replay of captured requests

Impact

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, DigestAuth replay protection records lastNc plus one instead of the highest nonce-count value it has accepted. When a legitimate client sends noncontiguous nc values because of parallel or retried requests, the stored counter remains below the accepted maximum, allowing a passive observer to replay a captured Authorization header multiple times. Successful replays execute authenticated requests, including state-changing operations, as the captured user. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Affected packages

EcosystemPackageAffectedFixed in
mavenorg.http4s:http4s-ember-core_2.12<= 0.23.340.23.35
mavenorg.http4s:http4s-ember-core_2.13<= 0.23.340.23.35
mavenorg.http4s:http4s-ember-core_3<= 0.23.340.23.35

Weakness classification

References