Protected Fields Bypass in Parse Server Versions Prior to 8.6.93 and 9.0.0
CVE-2026-109303

5.3MEDIUM

Key Information:

Vendor

Parse-community

Status
Parse-server
Vendor
CVE Published:
12 October 2026

What is CVE-2026-109303?

The vulnerability in Parse Server allows authenticated users to exploit a flaw in the enforcement of identity-scoped protectedFields on count queries utilizing the $relatedTo operator. This oversight permits an authenticated user to access insights about protected relationship fields by revealing the sizes of confidential groups or block lists. By leveraging objectId constraints in combination with count queries, attackers might uncover sensitive memberships that should remain concealed, thereby breaching user privacy and data integrity.

Affected Version(s)

parse-server 9.0.0 < 9.10.1-alpha.13

parse-server 0 < 8.6.93

parse-server 9.10.1-alpha.13

References

https://github.com/parse-community/parse-server/security/...
vendor-advisory
https://www.vulncheck.com/advisories/parse-server-before-...
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

d3do-23
mtrezza
.