# CVE-2026-103437: ReadingLists imported metadata permits JavaScript URL XSS

> Reflected XSS in MediaWiki ReadingLists extension allows attackers to execute arbitrary JavaScript via imported metadata.

- **Severity:** Low 1.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:P/S:N/AU:Y/R:U/V:D/RE:M/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **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-c4w7-7m72-q5m9

## What is CVE-2026-103437?

CVE-2026-103437 is a low-severity cross-site scripting vulnerability in The Wikimedia Foundation MediaWiki ReadingLists extension, published on 30 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in The Wikimedia Foundation MediaWiki ReadingLists extension allows Reflected XSS.

This issue affects MediaWiki ReadingLists extension: 1.46 and 1.45.

Weakness: CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page)

## Which versions are affected by CVE-2026-103437?


## How do I fix CVE-2026-103437?

No fix has been published for CVE-2026-103437 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103437 being exploited?

There is no known exploitation of CVE-2026-103437 in the wild and no public exploit code.

Public exploit code:

- Sanitized report summary and local PoC for CVE-2026-103437 (github_poc): https://github.com/BomboBombone/CVE-2026-103437

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103437 and fix it if it is affected.

What it is: CVE-2026-103437 is a low-severity cross-site scripting vulnerability in The Wikimedia Foundation MediaWiki ReadingLists extension, published on 30 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-103437 in the wild and no public exploit code.

Affected product: The Wikimedia Foundation MediaWiki ReadingLists 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-2026-103437/ (Markdown: https://insights.sbomify.com/CVE-2026-103437/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103437
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103437
- OSV: https://osv.dev/vulnerability/CVE-2026-103437

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-103437/
Summaries are generated and may contain mistakes; the official description above is the record.