CVE-2026-104817

Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and response-size restrictions and performs synchronous XML parsing. An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled. This issue is fixed in version 2026.7.0.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:N/SA:L

EPSS

0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-25)

CWEs

CWE-405, CWE-770, CWE-918

Published

2026-10-13

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

References

• https://github.com/misskey-dev/misskey/commit/a12ee2e5d72c40252e11a164b2231667c9697667
• https://github.com/misskey-dev/misskey/releases/tag/2026.7.0
• https://github.com/misskey-dev/misskey/security/advisories/GHSA-4x7v-qx8f-g3p8

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