Jetty HTTP/2 Race Condition (CVE-2026-12611) Causes Server Unresponsive
CVE-2026-12611 Published on September 8, 2026
A client may issue HTTP/2 requests to a Jetty server that result in blocking writes that are never unblocked, eventually causing all threads to be blocked and the whole server to become unresponsive. This is caused by a race condition in the server when handling RST_STREAM frames and GOAWAY frames sent by the client. The race condition "resets" the HTTP2Flusher.terminated, previously set to a non-null value, to the null value, allowing entries to be enqueued in the flusher that however will never be processed. These unprocessed entries are the ones that would unblock the write-blocked threads.
Vulnerability Analysis
CVE-2026-12611 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-12611 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-12611
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Affected Versions
Eclipse Foundation Eclipse Jetty:- Version 12.1.0, <= 12.1.10 is affected.
- Version 12.0.0, <= 12.0.37 is affected.
- Version 11.00, <= 11.0.31 is affected.
- Version 10.0.0, <= 10.0.31 is affected.
- Version 9.4.36, <= 9.4.63 is affected.