CVE-2026-9563 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability. A fix is available — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-9563 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
In Eclipse Parsson published Maven Central artifacts before version 1.1.8, the JSON parser did not enforce a default maximum on the number of characters consumed while parsing a single JSON document. Applications that parse attacker- controlled JSON can be forced to consume excessive CPU and memory by processing very large documents, including large arrays, objects, strings, numbers, whitespace, or nested structures, resulting in a denial of service. Eclipse Parsson 1.1.8 introduces a configurable maximum parsing limit with a default limit of 15 million parser-consumed characters.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-9563, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important denial of service vulnerability in Eclipse Parsson, a JSON processing library. Applications within Red Hat products that parse untrusted or attacker-controlled JSON documents are susceptible to excessive CPU and memory consumption. This can lead to resource exhaustion and service unavailability…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift AI 2.25 | rhoai/odh-trustyai-service-rhel9:1788198681 | RHSA-2026:65126 |
| Red Hat OpenShift Dev Spaces 3.30 | devspaces/openvsx-rhel9:1787759145 | RHSA-2026:62260 |
Frequently Asked Questions
Is CVE-2026-9563 in your dependencies?
Find it across , including transitive dependencies.