Vulnerability · Published Aug 3, 2026 · Assigned by GitHub_M

CVE-2026-48115Misskey: Improper Authorization in the Announcements API

Medium 6.3

In plain English

A medium-severity security flaw in misskey from misskey-dev. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).

Severity (CVSS 4.0)6.3Medium

Exploit odds (30 days)0.4%top 63.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Misskey is an open source, federated social media platform. All Misskey servers running versions 2024.5.0 and later, but prior to 2026.5.4, contain a vulnerability in the Server Announcements API where insufficient permission checks allow attackers to access limited portions of data that they normally couldn't view. This vulnerability occurs whether or not federation is enabled. This issue has been fixed in version 2026.5.4.

Affected products (as reported)

Vendor	Product	Versions
misskey-dev	misskey	>= 2024.5.0, < 2026.5.4

Weakness: CWE-285 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/misskey-dev/misskey/security/advisories/GHSA-j49q-76hx-mv8f x_refsource_CONFIRM
https://github.com/misskey-dev/misskey/releases/tag/2026.5.4 x_refsource_MISC