# CVE-2023-25154: Cross site scripting (XSS) of ActivityPub URI in misskey

> Attackers can execute JavaScript in the victim's browser via malicious ActivityPub URIs in Misskey, requiring an upgrade to fix.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 22 Feb 2023
- **Updated:** 10 Mar 2025
- **Also known as:** GHSA-pfp5-r48x-fg25

## What is CVE-2023-25154?

CVE-2023-25154 is a high-severity cross-site scripting vulnerability in misskey-dev misskey, published on 22 Feb 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Misskey is an open source, decentralized social media platform. In versions prior to 13.5.0 the link to the instance to the sender that appears when viewing a user or note received through ActivityPub is not properly validated, so by inserting a URL with a javascript scheme an attacker may execute JavaScript code in the context of the recipient. This issue has been fixed in version 13.5.0. Users are advised to upgrade. Users unable to upgrade should not "view on remote" for untrusted instances.

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

## Which versions are affected by CVE-2023-25154?

It affects 1 product.


Products: Misskey Misskey.

## How do I fix CVE-2023-25154?

No fix has been published for CVE-2023-25154 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-25154 being exploited?

There is no known exploitation of CVE-2023-25154 in the wild and no public exploit code.

## Other vulnerabilities in misskey-dev misskey

- [CVE-2025-25306](https://insights.sbomify.com/CVE-2025-25306/): Misskey's Incomplete Patch of CVE-2024-52591 Leads to Forgery of Federated Notes (critical 9.3)
- [CVE-2023-49079](https://insights.sbomify.com/CVE-2023-49079/): Misskey's missing signature validation allows arbitrary users to impersonate any remote user. (critical 9.3)
- [CVE-2026-28431](https://insights.sbomify.com/CVE-2026-28431/): Misskey lacks proper authorization checks and input validation (critical 9.2)
- [CVE-2023-52139](https://insights.sbomify.com/CVE-2023-52139/): Misskey vulnerable to improper authorization when accessing with third-party application (critical 9.1)
- [CVE-2024-52590](https://insights.sbomify.com/CVE-2024-52590/): Missing validation allows spoofed profiles in Misskey (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-25154 and fix it if it is affected.

What it is: CVE-2023-25154 is a high-severity cross-site scripting vulnerability in misskey-dev misskey, published on 22 Feb 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-25154 in the wild and no public exploit code.

Affected product: misskey-dev misskey. 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-2023-25154/ (Markdown: https://insights.sbomify.com/CVE-2023-25154/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-25154
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-25154
- OSV: https://osv.dev/vulnerability/CVE-2023-25154

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-25154/
Summaries are generated and may contain mistakes; the official description above is the record.