CVE-2026-1605

Description (as reported)

There is a memory leak when using GzipHandler in jetty-12.0.30 that can cause off-heap OOMs. This can be used for DoS attacks so I'm reporting this as a vulnerability.

The leak is created by requests where the request is inflated (Content-Encoding: gzip) and the response is not deflated (no Accept-Encoding: gzip). In these conditions, a new inflator will be created by GzipRequest and never released back into GzipRequest.__inflaterPool because gzipRequest.destory() is not called.

In heap dumps one can see thousands of java.util.zip.Inflator objects, which use both Java heaps and native memory. Leaking native memory causes of off-heap OOMs.

Code path in GzipHandler.handle():

1. Line 601: GzipRequest is created when request inflation is needed.
2. Lines 611-616: The callback is only wrapped in GzipResponseAndCallback when both inflation and deflation are needed.
3. Lines 619-625: If the handler accepts the request (returns true), gzipRequest.destroy() is only called in the "request not accepted" path (returns false)

When deflation is needed, GzipResponseAndCallback (lines 102 and 116) properly calls gzipRequest.destroy() in its succeeded() and failed() methods. But this wrapper is only created when deflation is needed.

Possible fix:
The callback should be wrapped whenever a GzipRequest is created, not just when deflation is needed. This ensures gzipRequest.destroy() is always called when the request completes.

Workarounds

Disable GzipHandler.

References

https://github.com/jetty/jetty.project/issues/14260

https://gitlab.eclipse.org/security/cve-assignment/-/issues/79

The leak causes the JVM to crash with OOME.

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

CVE-2026-1605 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 (12.1.6, 12.0.32); upgrading removes the vulnerable code path.

Kodem intelligence

No patches yet.

1. What is CVE-2026-1605? CVE-2026-1605 is a high-severity uncontrolled resource consumption vulnerability in org.eclipse.jetty:jetty-server (maven), affecting versions >= 12.1.0, <= 12.1.5. It is fixed in 12.1.6, 12.0.32. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-1605? CVE-2026-1605 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.
3. Which versions of org.eclipse.jetty:jetty-server are affected by CVE-2026-1605? org.eclipse.jetty:jetty-server (maven) versions >= 12.1.0, <= 12.1.5 is affected.
4. Is there a fix for CVE-2026-1605? Yes. CVE-2026-1605 is fixed in 12.1.6, 12.0.32. Upgrade to this version or later.
5. Is CVE-2026-1605 exploitable, and should I be worried? Whether CVE-2026-1605 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
6. What actually determines whether CVE-2026-1605 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.
7. How do I fix CVE-2026-1605?
   • Upgrade org.eclipse.jetty:jetty-server to 12.1.6 or later
   • Upgrade org.eclipse.jetty:jetty-server to 12.0.32 or later