# CVE-2026-123844: In JetBrains IntelliJ IDEA before 2026.3 sSRF was possible via custom plugin repositories


- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 6 Nov 2026
- **Updated:** 6 Nov 2026
- **Also known as:** GHSA-36hr-rxj9-g4xm

## What is CVE-2026-123844?

CVE-2026-123844 is a medium-severity vulnerability in JetBrains IntelliJ IDEA, published on 6 Nov 2026. 

### Official description

In JetBrains IntelliJ IDEA before 2026.3 sSRF was possible via custom plugin repositories

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-123844?

It affects 1 product.


Products: JetBrains IntelliJ IDEA.

## How do I fix CVE-2026-123844?

No fix has been published for CVE-2026-123844 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123844 being exploited?

There is no known exploitation of CVE-2026-123844 in the wild and no public exploit code.

## Other vulnerabilities in JetBrains IntelliJ IDEA

- [CVE-2026-64812](https://insights.sbomify.com/CVE-2026-64812/): In JetBrains IntelliJ IDEA before 2026.2 unauthorized input injection was possible in a Remote Development session (critical 10.0)
- [CVE-2026-64813](https://insights.sbomify.com/CVE-2026-64813/): In JetBrains IntelliJ IDEA before 2026.2 unauthorized settings modification was possible in a Remote Development session (critical 10.0)
- [CVE-2020-11690](https://insights.sbomify.com/CVE-2020-11690/): In JetBrains IntelliJ IDEA before 2020.1, the license server could be resolved to an untrusted host in some cases. (critical 9.8)
- [CVE-2019-10104](https://insights.sbomify.com/CVE-2019-10104/): In several JetBrains IntelliJ IDEA Ultimate versions, an Application Server run configuration (for Tomcat, Jetty, Resin, or CloudBees) with (critical 9.8)
- [CVE-2019-9186](https://insights.sbomify.com/CVE-2019-9186/): In several JetBrains IntelliJ IDEA versions, a Spring Boot run configuration with the default setting allowed remote attackers to execute co (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123844 and fix it if it is affected.

What it is: CVE-2026-123844 is a medium-severity vulnerability in JetBrains IntelliJ IDEA, published on 6 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123844 in the wild and no public exploit code.

Affected product: JetBrains IntelliJ IDEA. 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-2026-123844/ (Markdown: https://insights.sbomify.com/CVE-2026-123844/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123844
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123844
- OSV: https://osv.dev/vulnerability/CVE-2026-123844

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123844/
Summaries are generated and may contain mistakes; the official description above is the record.