# CVE-2025-62665: Stored XSS through system messages in Skin:BlueSky

> Attackers can inject malicious scripts via system messages in the BlueSky skin, potentially compromising user sessions.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:L/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Oct 2025
- **Updated:** 20 Oct 2025
- **Also known as:** GHSA-h73w-rr6h-gjf4

## What is CVE-2025-62665?

CVE-2025-62665 is a medium-severity cross-site scripting vulnerability in Wikimedia Foundation Mediawiki - Skin:BlueSky, published on 18 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - Skin:BlueSky allows Stored XSS.This issue affects Mediawiki - Skin:BlueSky: from master before 1.39.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-62665?


## How do I fix CVE-2025-62665?

No fix has been published for CVE-2025-62665 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-62665 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62665 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-62665 and fix it if it is affected.

What it is: CVE-2025-62665 is a medium-severity cross-site scripting vulnerability in Wikimedia Foundation Mediawiki - Skin:BlueSky, published on 18 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62665 exists.

Affected product: Wikimedia Foundation Mediawiki - Skin:BlueSky. 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-2025-62665/ (Markdown: https://insights.sbomify.com/CVE-2025-62665/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-62665
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-62665
- OSV: https://osv.dev/vulnerability/CVE-2025-62665

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-62665/
Summaries are generated and may contain mistakes; the official description above is the record.