Prototype Pollution in Parse-Community Parse-Server
CVE-2026-121965
Parse Server before 8.6.113 and 9.0.0 before 9.10.6-alpha.5 contains a prototype pollution vulnerability when building objects for Cloud Code triggers and LiveQuery, where a dot notation key whose intermediate segment resolves through an inherited member writes onto a process-wide built-in. Clients with write access to an object in a class with a trigger or LiveQuery can corrupt a built-in function, making unrelated requests fail until restart and denying service to all clients and hosted applications.
Vulnerability class: Prototype Pollution
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/parse-community/parse-server/security/advisories/GHSA-95hp-82c6-25q5 (vendor-advisory)
- github.com/parse-community/parse-server/pull/10810 (issue-tracking, patch)
- github.com/parse-community/parse-server/pull/10811 (issue-tracking, patch)
- www.vulncheck.com/advisories/parse-server-before-8.6.113-and-9.10.6-alpha.5-pro… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121965?
- CVE-2026-121965 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 5.3/10. Published 2026-11-04.
- How severe is CVE-2026-121965?
- Medium severity. CVSS v3 base score is 5.3 out of 10.