Quick answers
- Is CVE-2026-104817 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-104817 being exploited in the wild.
- How severe is CVE-2026-104817?
- Informational severity, published 13 October 2026.
- Which products and versions are affected?
- Misskey 12.112.1 to 2026.6.x.
- Is there a fix for CVE-2026-104817?
- Yes: fixed in 2026.7.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-104817 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-104817?
- Check whether you run Misskey at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 2026.7.0
Technical details
The fetch-rss API endpoint accepted unauthenticated requests without rate limiting or response-size caps and performed synchronous XML parsing, allowing attackers to exhaust server resources, amplify traffic to external servers, or probe internal network services even when federation was disabled. The vulnerability affects versions from 12.112.1 through 2026.6.x and is fixed in version 2026.7.0, which introduces URL length limits (8192 bytes), response size caps (1 MB), and proper error handling.
Affected products
- Misskey Misskey 12.112.1 to 2026.6.x
Timeline
- 2026-10-13: disclosed