Http4s: DigestAuth nonce map grows unbounded

Answer in brief

CVE-2026-69208 records a High severity (CVSS 7.5) vulnerability in Http4s: DigestAuth nonce map grows unbounded. The current sources do not mark it as known exploited. The current feed maps http4s/http4s (generic), org.http4s:http4s-ember-server_2.12 (maven), org.http4s:http4s-ember-server_2.13 (maven), org.http4s:http4s-ember-server_2.13 (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 15, 2026Source checked Sep 15, 2026First seen by HOL Sep 15, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 6 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps http4s/http4s (generic), org.http4s:http4s-ember-server_2.12 (maven), org.http4s:http4s-ember-server_2.13 (maven), org.http4s:http4s-ember-server_2.13 (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
http4s/http4sgeneric	< 0.23.35 \|\| >= 1.0.0-M1, < 1.0.0-M47	Not reported
org.http4s:http4s-ember-server_2.12maven	<=0.23.34	0.23.35
org.http4s:http4s-ember-server_2.13maven	<=0.23.34	0.23.35
org.http4s:http4s-ember-server_2.13maven	>=1.0.0-M1,<=1.0.0-M46	1.0.0-M47
org.http4s:http4s-ember-server_3maven	<=0.23.34	0.23.35
org.http4s:http4s-ember-server_3maven	>=1.0.0-M1,<=1.0.0-M46	1.0.0-M47

Recommended response

Check inventory. Check lockfiles and deployed manifests for http4s/http4s, org.http4s:http4s-ember-server_2.12, org.http4s:http4s-ember-server_2.13.
Review the reported fix. Update org.http4s:http4s-ember-server_2.12 to 0.23.35; org.http4s:http4s-ember-server_2.13 to 0.23.35; org.http4s:http4s-ember-server_2.13 to 1.0.0-M47; org.http4s:http4s-ember-server_3 to 0.23.35; org.http4s:http4s-ember-server_3 to 1.0.0-M47 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.