# CVE-2026-103442: MergeAccount PHP object injection via session-key substitution

> Attackers can execute arbitrary code via PHP object injection in the MediaWiki CentralAuth extension by manipulating session keys.

- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:P/S:N/AU:Y/R:U/V:D/RE:M/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-7c6r-9xcw-h46m

## What is CVE-2026-103442?

CVE-2026-103442 is a high-severity code injection vulnerability in The Wikimedia Foundation MediaWiki CentralAuth extension, published on 30 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

External control of system or configuration setting vulnerability in The Wikimedia Foundation MediaWiki CentralAuth extension allows Code Injection.

This issue affects MediaWiki CentralAuth extension: 1.46, 1.45, and 1.43.

Weakness: CWE-15 (External Control of System or Configuration Setting)

## Which versions are affected by CVE-2026-103442?


## How do I fix CVE-2026-103442?

No fix has been published for CVE-2026-103442 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103442 being exploited?

There is no known exploitation of CVE-2026-103442 in the wild and no public exploit code.

Public exploit code:

- Sanitized report summary and local PoC for CVE-2026-103442 (github_poc): https://github.com/BomboBombone/CVE-2026-103442

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103442 and fix it if it is affected.

What it is: CVE-2026-103442 is a high-severity code injection vulnerability in The Wikimedia Foundation MediaWiki CentralAuth extension, published on 30 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-103442 in the wild and no public exploit code.

Affected product: The Wikimedia Foundation MediaWiki CentralAuth extension. 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-2026-103442/ (Markdown: https://insights.sbomify.com/CVE-2026-103442/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103442
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103442
- OSV: https://osv.dev/vulnerability/CVE-2026-103442

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103442/
Summaries are generated and may contain mistakes; the official description above is the record.