Resource exhaustion in Http4s
CVE-2026-69208
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.
Vulnerability class: DoS (Denial of Service)
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Http4s — versions < 0.23.35, >= 1.0.0-M1, < 1.0.0-M47
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-69208?
- CVE-2026-69208 is a high-severity vulnerability in Http4s, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-09-15.
- How severe is CVE-2026-69208?
- High severity. CVSS v3 base score is 7.5 out of 10.