parse-server: Improper Access Control
CVE-2026-30966 is a critical-severity improper access control vulnerability in parse-server from Parse-community, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected parse-server versions: >= 9.0.0 < 9.5.2-alpha.7; < 8.6.20. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of parse-server you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Parse-community | parse-server | >= 9.0.0 < 9.5.2-alpha.7; < 8.6.20 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L. Scored by CNA (github.com).
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/parse-community/parse-server/releases/tag/8.6.20Product, Release Notes
- github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.7Product, Release Notes
Other vulnerabilities in parse-server
- 7.5 High severity
- 8.8 High severity
- 7.4 High severity
- 8.2 High severity
- 7.5 High severity
- 7.4 High severity
Recent Improper Access Control vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 8.1 High severity
- 7.1 High severity
Spotted an error? Tell us.