Summary
Denial of service (via resource exhaustion) due to improper input validation in third-party identifier endpoint
Workarounds
There are no known workarounds.
References
n/a
For more information
If you have any questions or comments about this advisory, email us at [email protected].
Impact
Missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion.
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
Affected versions
Security releases
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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The issue is fixed by https://github.com/matrix-org/synapse/pull/9855.
Frequently Asked Questions
- What is GHSA-7H5V-85W9-PQ6C? GHSA-7H5V-85W9-PQ6C is a medium-severity uncontrolled resource consumption vulnerability in matrix-synapse (pip), affecting versions < 1.33.0. It is fixed in 1.33.0. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- Which versions of matrix-synapse are affected by GHSA-7H5V-85W9-PQ6C? matrix-synapse (pip) versions < 1.33.0 is affected.
- Is there a fix for GHSA-7H5V-85W9-PQ6C? Yes. GHSA-7H5V-85W9-PQ6C is fixed in 1.33.0. Upgrade to this version or later.
- Is GHSA-7H5V-85W9-PQ6C exploitable, and should I be worried? Whether GHSA-7H5V-85W9-PQ6C 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 GHSA-7H5V-85W9-PQ6C 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 GHSA-7H5V-85W9-PQ6C? Upgrade
matrix-synapseto 1.33.0 or later.