What is CVE-2026-69208?

CVE-2026-69208 is a high-severity uncontrolled resource consumption vulnerability in org.http4s:http4s-ember-server_2.12 (maven), affecting versions <= 0.23.34. It is fixed in 0.23.35, 1.0.0-M47. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.

How severe is CVE-2026-69208?

CVE-2026-69208 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2026-69208?

org.http4s:http4s-ember-server_2.12 (maven) versions <= 0.23.34; org.http4s:http4s-ember-server_2.13 (maven) versions <= 0.23.34; org.http4s:http4s-ember-server_3 (maven) versions <= 0.23.34.

Is there a fix for CVE-2026-69208?

Yes. CVE-2026-69208 is fixed in 0.23.35, 1.0.0-M47. Upgrade to this version or later.

Is CVE-2026-69208 exploitable, and should I be worried?

Whether CVE-2026-69208 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-69208 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2026-69208

Q: How severe is CVE-2026-69208?

CVE-2026-69208 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which packages are affected by CVE-2026-69208?

org.http4s:http4s-ember-server_2.12 (maven) versions <= 0.23.34; org.http4s:http4s-ember-server_2.13 (maven) versions <= 0.23.34; org.http4s:http4s-ember-server_3 (maven) versions <= 0.23.34.

Q: Is there a fix for CVE-2026-69208?

Yes. CVE-2026-69208 is fixed in 0.23.35, 1.0.0-M47. Upgrade to this version or later.

Q: Is CVE-2026-69208 exploitable, and should I be worried?

Whether CVE-2026-69208 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-69208 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-69208?

Upgrade: org.http4s:http4s-ember-server_2.12 to 0.23.35 or later, org.http4s:http4s-ember-server_2.13 to 0.23.35 or later, org.http4s:http4s-ember-server_3 to 0.23.35 or later, org.http4s:http4s-ember-server_2.13 to 1.0.0-M47 or later, org.http4s:http4s-ember-server_3 to 1.0.0-M47 or later.

Summary

Http4s: DigestAuth nonce map grows unbounded

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.

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.

Impact

Unauthenticated remote denial of service (gradual heap exhaustion / OOM) against
any service using DigestAuth. The leak is persistent.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-69208 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.23.35, 1.0.0-M47); upgrading removes the vulnerable code path.

Affected versions

org.http4s:http4s-ember-server_2.12 (<= 0.23.34) org.http4s:http4s-ember-server_2.13 (<= 0.23.34) org.http4s:http4s-ember-server_3 (<= 0.23.34) org.http4s:http4s-ember-server_2.13 (>= 1.0.0-M1, <= 1.0.0-M46) org.http4s:http4s-ember-server_3 (>= 1.0.0-M1, <= 1.0.0-M46)

Security releases

org.http4s:http4s-ember-server_2.12 → 0.23.35 (maven) org.http4s:http4s-ember-server_2.13 → 0.23.35 (maven) org.http4s:http4s-ember-server_3 → 0.23.35 (maven) org.http4s:http4s-ember-server_2.13 → 1.0.0-M47 (maven) org.http4s:http4s-ember-server_3 → 1.0.0-M47 (maven)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Upgrade the following packages to resolve this vulnerability:

org.http4s:http4s-ember-server_2.12 to 0.23.35 or later; org.http4s:http4s-ember-server_2.13 to 0.23.35 or later; org.http4s:http4s-ember-server_3 to 0.23.35 or later; org.http4s:http4s-ember-server_2.13 to 1.0.0-M47 or later; org.http4s:http4s-ember-server_3 to 1.0.0-M47 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2026-69208? CVE-2026-69208 is a high-severity uncontrolled resource consumption vulnerability in org.http4s:http4s-ember-server_2.12 (maven), affecting versions <= 0.23.34. It is fixed in 0.23.35, 1.0.0-M47. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
How severe is CVE-2026-69208? CVE-2026-69208 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which packages are affected by CVE-2026-69208?
- org.http4s:http4s-ember-server_2.12 (maven) (versions <= 0.23.34)
- org.http4s:http4s-ember-server_2.13 (maven) (versions <= 0.23.34)
- org.http4s:http4s-ember-server_3 (maven) (versions <= 0.23.34)
Is there a fix for CVE-2026-69208? Yes. CVE-2026-69208 is fixed in 0.23.35, 1.0.0-M47. Upgrade to this version or later.
Is CVE-2026-69208 exploitable, and should I be worried? Whether CVE-2026-69208 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-69208 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-69208?
- Upgrade org.http4s:http4s-ember-server_2.12 to 0.23.35 or later
- Upgrade org.http4s:http4s-ember-server_2.13 to 0.23.35 or later
- Upgrade org.http4s:http4s-ember-server_3 to 0.23.35 or later
- Upgrade org.http4s:http4s-ember-server_2.13 to 1.0.0-M47 or later
- Upgrade org.http4s:http4s-ember-server_3 to 1.0.0-M47 or later