GHSA-5j86-7r7m-p8h6 BIT-parse-2026-30939 CVE-2026-30939
Parse Server has Denial of Service (DoS) and Cloud Function Dispatch Bypass via Prototype Chain Resolution
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.51%
- Chance of exploitation in the next 30 days. Higher than 43.42% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Fix
8.6.13- Upgrade parse-server to this version or later
Description
Impact
An unauthenticated attacker can crash the Parse Server process by calling a Cloud Function endpoint with a prototype property name as the function name. The server recurses infinitely, causing a call stack size error that terminates the process.
Other prototype property names bypass Cloud Function dispatch validation and return HTTP 200 responses, even though no such Cloud Functions are defined. The same applies to dot-notation traversal.
All Parse Server deployments that expose the Cloud Function endpoint are affected.
Patches
The internal handler registries for Cloud Functions, Jobs, Triggers, and Validators have been changed to prevent prototype chain properties from being resolved.
Workarounds
Place a reverse proxy or WAF in front of Parse Server and block requests to Object.prototype property names.
References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-5j86-7r7m-p8h6
- Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.2
- Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.13
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| parse-server | < 8.6.13 |
8.6.13 |
| parse-server | >= 9.0.0-alpha.1, < 9.5.1-alpha.2 |
9.5.1-alpha.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
parse-server npm → 8.6.13
- npm
npm install parse-server@8.6.13- yarn
yarn add parse-server@8.6.13- pnpm
pnpm add parse-server@8.6.13
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
How to prevent it
- Implementation: By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
- Architecture and Design: By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
- Implementation: When handling untrusted objects, validating using a schema can be used.
- Implementation: By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.
- Implementation: Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-r899-h629-j84r Parse Server vulnerable to stored XSS via malformed Content-Type bypassing file upload extension blocklist | Low | Also affects parse-server |
| GHSA-97pr-9hgg-3p8r parse-server: LiveQuery discloses object data to a subscriber across an ACL read-access change | Low | Also affects parse-server |
| GHSA-v8x7-r927-cc93 parse-server: Stored XSS via non-standard file extension bypassing file upload extension blocklist | Low | Also affects parse-server |
| GHSA-cgxm-vr2f-6fj8 parse-server: Denial of service via exponential-time processing of deeply nested query operators | High | Also affects parse-server |
| GHSA-wmwx-jr2p-4j4r parse-server: Relation `$relatedTo` query bypasses `protectedFields` and owning-object ACL | Medium | Also affects parse-server |
| GHSA-75v4-m273-5j49 parse-server: Endpoints `/login` and `/verifyPassword` disclose MFA secrets and protected fields when `_User` get is denied | Medium | Also affects parse-server |
| GHSA-7wqv-xjf3-x35v parse-server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist | Low | Also affects parse-server |
| GHSA-p84r-h6rx-f2xr parse-server: Server option routeAllowList is bypassable through batch sub-requests | Medium | Also affects parse-server |
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