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OpenAdvisories
Medium · 5.9 CVE-2025-66560 EUVD-2026-1178GHSA-5rfx-cp42-p624

Quarkus REST has potential worker thread starvation when HTTP connection is closed while waiting to write

Published Jan 7, 2026 · Updated Jan 7, 2026 · Assigned by GitHub_M

Description

Quarkus is a Cloud Native, (Linux) Container First framework for writing Java applications. Prior to versions 3.31.0, 3.27.2, and 3.20.5, a vulnerability exists in the HTTP layer of Quarkus REST related to response handling. When a response is being written, the framework waits for previously written response chunks to be fully transmitted before proceeding. If the client connection is dropped during this waiting period, the associated worker thread is never released and becomes permanently blocked. Under sustained or repeated occurrences, this can exhaust the available worker threads, leading to degraded performance, or complete unavailability of the application. This issue has been patched in versions 3.31.0, 3.27.2, and 3.20.5. A workaround involves implementing a health check that monitors the status and saturation of the worker thread pool to detect abnormal thread retention early.

Affected products

VendorProductAffectedFixed
quarkusio quarkus >= 3.30.0, < 3.31.0, >= 3.21.0, < 3.27.2, < 3.20.5 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling keycloak-26.4-iamguarded-compat No fix yet —
Wolfi rolling keycloak-26.5 +1 26.5.1-r0 —

Affected packages

EcosystemPackageAffectedFixedRecord
Maven io.quarkus:quarkus-rest < 3.20.5 3.20.5 GHSA-5rfx-cp42-p624
Maven io.quarkus:quarkus-rest >= 3.21.0, < 3.27.2 3.27.2 GHSA-5rfx-cp42-p624
Maven io.quarkus:quarkus-rest >= 3.30.0, < 3.31.0 3.31.0 GHSA-5rfx-cp42-p624

Advisories 1

References