Vulnerabilities in pkg:maven/org.http4s/http4s-ember-server_2.13

PACKAGE
Advisory Identifier: GHSA-fm4g-76c9-7w69
Advisory Summary

CVE-2026-69208 is a HIGH (CVSS 7.5) digestauth nonce map grows unbounded vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Http4s libraries in the Maven ecosystem. The issue involves digestauth nonce map grows unbounded. Remediation is available by upgrading affected packages to version 0.23.35, 1.0.0-M47.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:maven/org.http4s/http4s-ember-server_2.13

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:maven/org.http4s/http4s-ember-server_2.13. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-fm4g-76c9-7w69 CVE-2026-69208 HIGH Http4s: DigestAuth nonce map grows unbounded

CVE-2026-69208 at a Glance

CVE Identifier CVE-2026-69208
GHSA Identifier GHSA-fm4g-76c9-7w69
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Http4s
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-69208

To remediate this vulnerability, upgrade all affected Http4s dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.http4s:http4s-ember-server_2.12 fixed: 0.23.35
<dependency>
    <groupId>org.http4s</groupId>
    <artifactId>http4s-ember-server_2.12</artifactId>
    <version>0.23.35</version>
</dependency>
org.http4s:http4s-ember-server_2.13 fixed: 0.23.35
<dependency>
    <groupId>org.http4s</groupId>
    <artifactId>http4s-ember-server_2.13</artifactId>
    <version>0.23.35</version>
</dependency>
org.http4s:http4s-ember-server_3 fixed: 0.23.35
<dependency>
    <groupId>org.http4s</groupId>
    <artifactId>http4s-ember-server_3</artifactId>
    <version>0.23.35</version>
</dependency>
org.http4s:http4s-ember-server_2.13 fixed: 1.0.0-M47
<dependency>
    <groupId>org.http4s</groupId>
    <artifactId>http4s-ember-server_2.13</artifactId>
    <version>1.0.0-M47</version>
</dependency>
org.http4s:http4s-ember-server_3 fixed: 1.0.0-M47
<dependency>
    <groupId>org.http4s</groupId>
    <artifactId>http4s-ember-server_3</artifactId>
    <version>1.0.0-M47</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

mvn dependency:tree -Dincludes=org.http4s

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-69208, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.http4s

Analyze the terminal output to locate any version of Http4s in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.23.35), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.http4s command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Http4s, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The `DigestAuth` server middleware's stale-nonce cleanup uses an inverted comparison: it removes *fresh* nonces and stops at the first *stale* one. Because a new nonce is created for every unauthenticated challenge, an attacker can drive the nonce map to grow without bound until the JVM runs out of heap. ## Impact Unauthenticated remote denial of service (gradual heap exhaustion / OOM) against any service using DigestAuth. The leak is persistent. ## Preconditions - Application uses `DigestAuth` on at least one route. ## Workarounds - Front the DigestAuth protected routes with a rate limiter to slow the leak. - Restart periodically. ## Fixes - The eviction logic is corrected. - A max cache size of 1000000 is imposed to protected against a burst between evictions. This limit is not yet configurable.

CVE-2026-69208 Affected Http4s Versions

5 component(s)
Fixed Versions:
0.23.351.0.0-M47
Product / Package Ecosystem Affected Versions Fixed Version
org.http4s:http4s-ember-server_2.12
Maven
< 0.23.35
0.23.35
org.http4s:http4s-ember-server_2.13
Maven
< 0.23.35
0.23.35
org.http4s:http4s-ember-server_3
Maven
< 0.23.35
0.23.35
org.http4s:http4s-ember-server_2.13
Maven
≥ 1.0.0-M1
< 1.0.0-M47
1.0.0-M47
org.http4s:http4s-ember-server_3
Maven
≥ 1.0.0-M1
< 1.0.0-M47
1.0.0-M47

References

Frequently Asked Questions

What is CVE-2026-69208?
CVE-2026-69208 is a security vulnerability in Http4s involving DigestAuth nonce map grows unbounded under CWE-400: Uncontrolled Resource Consumption.
Which Http4s versions are affected?
Affected versions include releases prior to 0.23.35, 1.0.0-M47 across affected packages: org.http4s:http4s-ember-server_2.12, org.http4s:http4s-ember-server_2.13, org.http4s:http4s-ember-server_3.
What version fixes CVE-2026-69208?
Upgrading to 0.23.35, 1.0.0-M47 (or the latest patched release for your respective branch) resolves the vulnerability.
Is http4s-ember-server_2.12 affected?
Yes, org.http4s:http4s-ember-server_2.12 is affected in releases prior to 0.23.35. Upgrade your dependency to 0.23.35 or later.
Is http4s-ember-server_2.13 affected?
Yes, org.http4s:http4s-ember-server_2.13 is affected in releases prior to 0.23.35, 1.0.0-M47. Upgrade your dependency to 0.23.35, 1.0.0-M47 or later.
What is the CVSS score of CVE-2026-69208?
CVE-2026-69208 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-69208?
CVE-2026-69208 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check Maven dependencies for CVE-2026-69208?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.http4s'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fm4g-76c9-7w69",
  "modified" : "2026-09-15T19:54:37Z",
  "published" : "2026-09-15T19:54:37Z",
  "aliases" : [ "CVE-2026-69208" ],
  "summary" : "Http4s: DigestAuth nonce map grows unbounded",
  "details" : "The `DigestAuth` server middleware's stale-nonce cleanup uses an inverted comparison: it removes *fresh* nonces and stops at the first *stale* one.  Because a new nonce is created for every unauthenticated challenge, an attacker can drive the nonce map to grow without bound until the JVM runs out of heap.\n\n## Impact\n\nUnauthenticated remote denial of service (gradual heap exhaustion / OOM) against\nany service using DigestAuth.  The leak is persistent.\n\n## Preconditions\n\n- Application uses `DigestAuth` on at least one route.\n\n## Workarounds\n\n- Front the DigestAuth protected routes with a rate limiter to slow the leak.\n- Restart periodically.\n\n## Fixes\n\n- The eviction logic is corrected.\n- A max cache size of 1000000 is imposed to protected against a burst between evictions.  This limit is not yet configurable.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.http4s:http4s-ember-server_2.12"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.23.35"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.23.34"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.http4s:http4s-ember-server_2.13"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.23.35"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.23.34"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.http4s:http4s-ember-server_3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.23.35"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.23.34"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.http4s:http4s-ember-server_2.13"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0-M1"
      }, {
        "fixed" : "1.0.0-M47"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.0.0-M46"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.http4s:http4s-ember-server_3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0-M1"
      }, {
        "fixed" : "1.0.0-M47"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.0.0-M46"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/http4s/http4s/security/advisories/GHSA-fm4g-76c9-7w69"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/http4s/http4s/commit/8cfeda8472954d631dfbe5dc026463a27653e482"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/http4s/http4s"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/http4s/http4s/releases/tag/v0.23.35"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-401" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-15T19:54:37Z",
    "nvd_published_at" : null
  }
}