# CVE-2026-123487: Parse Server 9.0.0 before 9.10.7-alpha.1 ReDoS via Email Validation Regex


- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 6 Nov 2026
- **Updated:** 6 Nov 2026
- **Also known as:** GHSA-9492-427f-466x, GHSA-r7pw-r949-xvmf

## What is CVE-2026-123487?

CVE-2026-123487 is a high-severity vulnerability in parse-community parse-server, published on 6 Nov 2026. 

### Official description

Parse Server before 8.6.115 and 9.0.0 before 9.10.7-alpha.1 validates user email address format with a regular expression whose run time grows quadratically with input length and that is applied without a length limit. An unauthenticated attacker who knows the application ID can send a sign-up request, or a logged-in user can update their own email, with a long crafted email address to block the Node.js event loop and deny service to all clients.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-123487?


## How do I fix CVE-2026-123487?

No fix has been published for CVE-2026-123487 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123487 being exploited?

There is no known exploitation of CVE-2026-123487 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123487 and fix it if it is affected.

What it is: CVE-2026-123487 is a high-severity vulnerability in parse-community parse-server, published on 6 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123487 in the wild and no public exploit code.

Affected product: parse-community parse-server. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-123487/ (Markdown: https://insights.sbomify.com/CVE-2026-123487/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123487
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123487
- OSV: https://osv.dev/vulnerability/CVE-2026-123487

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123487/
Summaries are generated and may contain mistakes; the official description above is the record.