Summary
Workarounds
There is no known workaround other than upgrading.
Impact
Parse Server's LiveQuery component does not enforce the requestComplexity.queryDepth configuration setting when processing WebSocket subscription requests. An attacker can send a subscription with deeply nested logical operators, causing excessive recursion and CPU consumption that degrades or disrupts service availability.
Deployments are affected when the LiveQuery WebSocket endpoint is reachable by untrusted clients.
CVE-2026-33508 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 (9.6.0-alpha.45, 8.6.56); upgrading removes the vulnerable code path.
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.
Remediation advice
The fix adds query condition depth validation to the LiveQuery subscription handler, enforcing the same requestComplexity.queryDepth limit that already protects REST API queries.
Frequently Asked Questions
- What is CVE-2026-33508? CVE-2026-33508 is a high-severity security vulnerability in parse-server (npm), affecting versions >= 9.0.0, < 9.6.0-alpha.45. It is fixed in 9.6.0-alpha.45, 8.6.56.
- How severe is CVE-2026-33508? CVE-2026-33508 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.
- Which versions of parse-server are affected by CVE-2026-33508? parse-server (npm) versions >= 9.0.0, < 9.6.0-alpha.45 is affected.
- Is there a fix for CVE-2026-33508? Yes. CVE-2026-33508 is fixed in 9.6.0-alpha.45, 8.6.56. Upgrade to this version or later.
- Is CVE-2026-33508 exploitable, and should I be worried? Whether CVE-2026-33508 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 CVE-2026-33508 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 CVE-2026-33508?
- Upgrade
parse-serverto 9.6.0-alpha.45 or later - Upgrade
parse-serverto 8.6.56 or later
- Upgrade