Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34363Parse Server: LiveQuery protected field leak via shared mutable state across concurrent subscribers
High 8.2
In plain English
A high-severity race condition 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 0.4% (higher than 31% 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 versions 8.6.65 and 9.7.0-alpha.9, when multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object. Additionally, when an afterEvent Cloud Code trigger is registered, one subscriber's trigger modifications can leak to other subscribers through the same shared mutable state. Any Parse Server deployment using LiveQuery with protected fields or afterEvent triggers is affected when multiple clients subscribe to the same class. This issue has been patched in versions 8.6.65 and 9.7.0-alpha.9.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | parse-server | 9.7.0-alpha.9 | GHSA-m983-v2ff-wq65 |
| npm | parse-server | 8.6.65 | GHSA-m983-v2ff-wq65 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| parse-community | parse-server | < 8.6.65>= 9.0.0, < 9.7.0-alpha.9 |
Weakness: CWE-362 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-m983-v2ff-wq65 x_refsource_CONFIRM
- https://github.com/parse-community/parse-server/pull/10330 x_refsource_MISC
- https://github.com/parse-community/parse-server/pull/10331 x_refsource_MISC
- https://github.com/parse-community/parse-server/commit/5834e29234593addaa0251a85f572ad4f376320b x_refsource_MISC
- https://github.com/parse-community/parse-server/commit/776c71c3078e77d38c94937f463741793609d055 x_refsource_MISC