CVE-2026-69208

Http4s: DigestAuth nonce map grows unbounded

Published Sep 15, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, the DigestAuth server middleware removes fresh nonces and stops eviction at the first stale nonce because its stale-nonce comparison is inverted. On an application that protects at least one route with DigestAuth, an unauthenticated attacker can repeatedly trigger authentication challenges, causing the persistent nonce map to grow until the JVM exhausts heap memory. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-fm4g-76c9-7w69 Http4s: DigestAuth nonce map grows unbounded
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Http4s
Http4s http4s
Vendors & Products Http4s
Http4s http4s
Type Values Removed Values Added
Description Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, the DigestAuth server middleware removes fresh nonces and stops eviction at the first stale nonce because its stale-nonce comparison is inverted. On an application that protects at least one route with DigestAuth, an unauthenticated attacker can repeatedly trigger authentication challenges, causing the persistent nonce map to grow until the JVM exhausts heap memory. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
Title Http4s: DigestAuth nonce map grows unbounded
Weaknesses CWE-400
CWE-401
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 17, 2026, 4:41 PM
Reserved
Aug 3, 2026, 4:57 PM
Status
Deferred
Published
Sep 15, 2026, 7:17 PM
Modified
Sep 17, 2026, 5:16 PM