All vulnerabilities
CVE-2026-109303GHSA-rmhf-xv62-rm99

parse-server: Parse Server before 8.6.93 and 9.0.0 before 9.10.1-alpha.13 protectedFields Bypass via Relation Count Query

parse-community parse-server
Open in ThreatlineRecord JSON
CVSS
5.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.20%Chance of exploitation activity in the next 30 days, higher than 9% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in9.10.1-alpha.13Also 8.6.93CVE List
Published12 Oct 2026Updated 13 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Parse Server before 8.6.93 and 9.0.0 before 9.10.1-alpha.13 does not enforce identity-scoped protectedFields (authenticated, role, or per-user groups) on count queries using the $relatedTo operator, exposing the size of protected Relation fields. An authenticated user who can read the owning object can combine counts with an objectId constraint as a membership oracle to reveal confidential memberships such as private groups or block lists.

Text from CVE List

Affected versions 4

  • parse-serveraffected: 9.0.0 before 9.10.1-alpha.13CVE List
  • parse-serverunaffected: 9.10.1-alpha.13CVE List
  • parse-serveraffected: all versions before 8.6.93CVE List
  • parse-serverunaffected: 8.6.93CVE List

References 2