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OpenAdvisories
Medium · 5.9 CVE-2026-69206 EUVD-2026-79236GHSA-9xww-74xv-gjfp

Http4s: DigestAuth allows replay of captured requests

Published Sep 15, 2026 · Updated Sep 16, 2026 · Assigned by GitHub_M

Description

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 products

VendorProductAffectedFixed
http4s http4s < 0.23.35, >= 1.0.0-M1, < 1.0.0-M47 —

Affected packages

EcosystemPackageAffectedFixedRecord
Maven org.http4s:http4s-ember-core_2.12 < 0.23.35 0.23.35 GHSA-9xww-74xv-gjfp
Maven org.http4s:http4s-ember-core_2.13 < 0.23.35 0.23.35 GHSA-9xww-74xv-gjfp
Maven org.http4s:http4s-ember-core_2.13 >= 1.0.0-M1, < 1.0.0-M47 1.0.0-M47 GHSA-9xww-74xv-gjfp
Maven org.http4s:http4s-ember-core_3 < 0.23.35 0.23.35 GHSA-9xww-74xv-gjfp
Maven org.http4s:http4s-ember-core_3 >= 1.0.0-M1, < 1.0.0-M47 1.0.0-M47 GHSA-9xww-74xv-gjfp

References