Vulnerability · Published Sep 15, 2026 · Assigned by GitHub_M

CVE-2026-69208Http4s: DigestAuth nonce map grows unbounded

High 7.5

In plain English

A high-severity uncontrolled resource consumption in http4s from http4s. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.8%top 44.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavenorg.http4s:http4s-ember-server_2.120.23.35GHSA-fm4g-76c9-7w69
Mavenorg.http4s:http4s-ember-server_2.130.23.35GHSA-fm4g-76c9-7w69
Mavenorg.http4s:http4s-ember-server_2.131.0.0-M47GHSA-fm4g-76c9-7w69
Mavenorg.http4s:http4s-ember-server_30.23.35GHSA-fm4g-76c9-7w69
Mavenorg.http4s:http4s-ember-server_31.0.0-M47GHSA-fm4g-76c9-7w69

Affected products (as reported)

VendorProductVersions
http4s http4s < 0.23.35>= 1.0.0-M1, < 1.0.0-M47

Weakness: CWE-400, CWE-401 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References