Auth bypass in Parse-Community Parse-Server
CVE-2026-34532
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.67 and 9.7.0-alpha.11, an attacker can bypass Cloud Function validator access controls by appending "prototype.constructor" to the function name in the URL. When a Cloud Function handler is declared using the function keyword and its validator is a plain object or arrow function, the trigger store traversal resolves the handler through its own prototype chain while the validator store fails to mirror this traversal, causing all access control enforcement to be skipped. This allows unauthenticated callers to invoke Cloud Functions that are meant to be protected by validators such as requireUser, requireMaster, or custom validation logic. This issue has been patched in versions 8.6.67 and 9.7.0-alpha.11.
Vulnerability class: Broken Access Control
EPSS: 0.003 (19.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Parse-community Parse-server — versions < 8.6.67, >= 9.0.0, < 9.7.0-alpha.11
- Parseplatform Parse-server — versions 9.7.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-34532?
- CVE-2026-34532 is a critical-severity vulnerability in Parse-Community Parse-Server, classified under Incorrect Authorization. CVSS score: 9.1/10. Published 2026-03-31.
- How severe is CVE-2026-34532?
- Critical severity. CVSS v3 base score is 9.1 out of 10.