Vulnerability · Published Mar 18, 2026 · Assigned by GitHub_M
CVE-2026-32770Parse Server: LiveQuery subscription with invalid regular expression crashes server
Medium 5.9
In plain English
A medium-severity security flaw in parse-server from parse-community. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.19 and 8.6.43, a remote attacker can crash the Parse Server by subscribing to a LiveQuery with an invalid regular expression pattern. The server process terminates when the invalid pattern reaches the regex engine during subscription matching, causing denial of service for all connected clients. The fix in 9.6.0-alpha.19 and 8.6.43 validates regular expression patterns at subscription time, rejecting invalid patterns before they are stored. Additionally, a defense-in-depth try-catch prevents any subscription matching error from crashing the server process. As a workaround, disable LiveQuery if it is not needed.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | parse-server | 9.6.0-alpha.19 | GHSA-827p-g5x5-h86c |
| npm | parse-server | 8.6.43 | GHSA-827p-g5x5-h86c |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| parse-community | parse-server | >= 9.0.0, < 9.6.0-alpha.19< 8.6.43 |
Weakness: CWE-248 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-827p-g5x5-h86c x_refsource_CONFIRM
- https://github.com/parse-community/parse-server/pull/10197 x_refsource_MISC
- https://github.com/parse-community/parse-server/pull/10199 x_refsource_MISC