CVE-2025-46340
7.2 · HIGHOverview
CVE-2025-46340 is a high-severity vulnerability affecting misskey misskey. It was published on May 5, 2025 and has a CVSS 3.1 base score of 7.2 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Misskey is an open source, federated social media platform. Starting in version 12.0.0 and prior to version 2025.4.1, due to an oversight in the validation performed in `UrlPreviewService` and `MkUrlPreview`, it is possible for an attacker to inject arbitrary CSS into the `MkUrlPreview` component. `UrlPreviewService.wrap` falls back to returning the original URL if it's using a protocol that is likely to not be understood by Misskey, IE something other than `http` or `https`. This both can de-anonymize users and_allow further attacks in the client. Additionally, `MkUrlPreview` doesn't escape CSS when applying a `background-image` property, allowing an attacker to craft a URL that applies arbitrary styles to the preview element. Theoretically, an attacker can craft a CSS injection payload to create a fake error message that can deceive the user into giving away their credentials or similar sensitive information. Version 2025.4.1 contains a patch for the issue.
Remediation
Check the references section for vendor advisories and patches from misskey. Update misskey to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| misskey | misskey | >= 12.0.0, < 2025.4.1 | Affected |
Frequently Asked Questions
What is CVE-2025-46340?
CVE-2025-46340 is a high-severity vulnerability affecting misskey misskey. It was published on May 5, 2025 and has a CVSS 3.1 base score of 7.2 (HIGH).
How severe is CVE-2025-46340?
This vulnerability has a CVSS 3.1 base score of 7.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-46340?
Check the references section for vendor advisories and patches from misskey. Update misskey to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-46340?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-46340 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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