# CVE-2026-30939: Parse Server has Denial of Service (DoS) and Cloud Function Dispatch Bypass via Prototype Chain Resolution

> Unauthenticated attackers can crash Parse Server via infinite recursion or bypass Cloud Function validation using prototype chain properties.

- **Severity:** High 8.8 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Mar 2026
- **Updated:** 10 Mar 2026
- **Also known as:** BIT-parse-2026-30939, GHSA-5j86-7r7m-p8h6

## What is CVE-2026-30939?

CVE-2026-30939 is a high-severity denial of service vulnerability in Parseplatform Parse-Server, published on 10 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.13 and 9.5.1-alpha.2, 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. This vulnerability is fixed in 8.6.13 and 9.5.1-alpha.2.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2026-30939?

5 open source packages ship an affected version, including parse-server and parse. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `parse-server` | npm | All versions | 8.6.13 |
| `parse-server` | npm | All versions | 8.6.13 |
| `parse-server` | npm | From 9.0.0-alpha.1 | 9.5.1-alpha.2 |
| `parse-server` | npm | From 9.0.0-alpha.1 | 9.5.1-alpha.2 |
| `parse` | Bitnami | All versions | 8.6.13, 9.5.1 |

Products: Parseplatform Parse-Server.

## How do I fix CVE-2026-30939?

Upgrade parse-server to a fixed version for your release line: 8.6.13 or 9.5.1-alpha.2.

## Is CVE-2026-30939 being exploited?

There is no known exploitation of CVE-2026-30939 in the wild and no public exploit code.

## Other vulnerabilities in Parseplatform Parse-Server

- [CVE-2026-30966](https://insights.sbomify.com/CVE-2026-30966/): Parse Server role escalation and CLP bypass via direct `_Join` table write (critical 10.0)
- [CVE-2024-27298](https://insights.sbomify.com/CVE-2024-27298/): Parse Server literalizeRegexPart SQL Injection (critical 10.0)
- [CVE-2022-24760](https://insights.sbomify.com/CVE-2022-24760/): Command Injection in Parse server (critical 10.0)
- [CVE-2026-30965](https://insights.sbomify.com/CVE-2026-30965/): Parse Server session token exfiltration via `redirectClassNameForKey` query parameter (critical 9.9)
- [CVE-2023-36475](https://insights.sbomify.com/CVE-2023-36475/): Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30939 and fix it if it is affected.

What it is: CVE-2026-30939 is a high-severity denial of service vulnerability in Parseplatform Parse-Server, published on 10 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-30939 in the wild and no public exploit code.

Affected packages and fixed versions:
- parse-server (npm): affected all versions; fixed in 8.6.13
- parse-server (npm): affected all versions; fixed in 8.6.13
- parse-server (npm): affected from 9.0.0-alpha.1; fixed in 9.5.1-alpha.2
- parse-server (npm): affected from 9.0.0-alpha.1; fixed in 9.5.1-alpha.2
- parse (Bitnami): affected all versions; fixed in 8.6.13, 9.5.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-30939/ (Markdown: https://insights.sbomify.com/CVE-2026-30939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30939
- OSV: https://osv.dev/vulnerability/CVE-2026-30939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30939/
Summaries are generated and may contain mistakes; the official description above is the record.