CVE-2026-104816: Misskey: Cross-site scripting in RSS feed item links

Severity: high (CVSS 8.5 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-16
Weakness: CWE-79

Description

Misskey is an open source, federated social media platform. From 12.0.0 until 2026.7.0, the RSS components display feed item links from configured feeds without verifying their URL schemes. Missing URL scheme verification allows an attacker who controls feed content to provide an unsafe-scheme link that causes script execution when a user clicks it in an RSS widget. This issue is fixed in version 2026.7.0.

Affected products

misskey-dev misskey: from 12.0.0, <= 13.14.2; from 2023.9.0-beta.1, < 2026.7.0

References

https://github.com/misskey-dev/misskey/commit/8dd59a8c06da49b8f302d902d73d04397ee29366
https://github.com/misskey-dev/misskey/pull/17831
https://github.com/misskey-dev/misskey/releases/tag/2026.7.0
https://github.com/misskey-dev/misskey/security/advisories/GHSA-p73x-6qrq-34jc

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