What’s Vulnerable › Vulnerabilities

CVE-2026-33429: Parse Server: Protected field change detection oracle via LiveQuery watch parameter

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-24 · updated 2026-06-17
• Weakness: CWE-203

Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.54 and 9.6.0-alpha.43, an attacker can subscribe to LiveQuery with a watch parameter targeting a protected field. Although the protected field value is properly stripped from event payloads, the presence or absence of update events reveals whether the protected field changed, creating a binary oracle. For boolean protected fields, the timing of change events is equivalent to knowing the field value. This issue has been patched in versions 8.6.54 and 9.6.0-alpha.43.

Affected products

• parse-community parse-server: before 8.6.54; from 9.0.0 before 9.6.0; 9.6.0-alpha1, 9.6.0-alpha10, 9.6.0-alpha11, 9.6.0-alpha12, 9.6.0-alpha13, 9.6.0-alpha14 (+36) — fixed in 8.6.54, 9.6.0

How to fix

Upgrade to a fixed version: parse-community parse-server 8.6.54, 9.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/parse-community/parse-server/commit/0c0a0a5a37ca821d2553119f2cb3be35322eda4b
• https://github.com/parse-community/parse-server/commit/c62eacaf38de86913f09240583448360b1cc8e67
• https://github.com/parse-community/parse-server/pull/10253
• https://github.com/parse-community/parse-server/pull/10254
• https://github.com/parse-community/parse-server/security/advisories/GHSA-qpc3-fg4j-8hgm

Get alerted when CVE-2026-33429 or the next vulnerability affects your stack