CVE-2026-30966: Parse Server has role escalation and CLP bypass via direct `_Join` table write

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.5%, percentile 44: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 44% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes parse-server (npm) >= 9.0.0-alpha.1, < 9.5.2-alpha.7, fixed in 9.5.2-alpha.7; parse-server (npm) < 8.6.20, fixed in 8.6.20. Check your lockfile, including transitive dependencies.

What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.7 and 8.6.20, Parse Server's internal tables, which store Relation field mappings such as role memberships, can be directly accessed via the REST API or GraphQL API by any client using only the application key. No master key is required. An attacker can create, read, update, or delete records in any internal relationship table. Exploiting this allows the attacker to inject themselves into any Parse Role, gaining all permissions associated with that role, including full read, write, and delete access to classes protected by role-based Class-Level Permissions (CLP). Similarly, writing to any such table that backs a Relation field used in a pointerFields CLP bypasses that access control. This vulnerability is fixed in 9.5.2-alpha.7 and 8.6.20.

From the GitHub advisory

Impact

Parse Server's internal tables, which store Relation field mappings such as role memberships, can be directly accessed via the REST API or GraphQL API by any client using only the application key. No master key is required.

An attacker can create, read, update, or delete records in any internal relationship table. Exploiting this allows the attacker to inject themselves into any Parse Role, gaining all permissions associated with that role, including full read, write, and delete access to classes protected by role-based Class-Level Permissions (CLP). Similarly, writing to any such table that backs a Relation field used in a pointerFields CLP bypasses that access control.

Patches

The fix blocks direct client access to internal relationship tables in Parse Server's role security enforcement. All create, find, get, update, and delete operations on these tables now require the master key or maintenance key.

Weakness type: CWE-284.

Product: parse-server (npm) · Assigned by: GitHub_M · Published: 2026-03-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.54% probability of exploitation activity in the next 30 days; percentile 44.

Timeline

• 2026-03-10 — CVE record published by GitHub_M
• 2026-03-11 — CVE record last updated
• 2026-03-11 — GitHub-reviewed advisory GHSA-5f92-jrq3-28rc published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-5f92-jrq3-28rc github.com
2. CVE.org record CVE-2026-30966 cve.org
3. NVD entry CVE-2026-30966 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical npm advisories · Today’s Security Digest