Medium severity · published Aug 3, 2026
CVE-2026-48115
Misskey: Improper Authorization in the Announcements API
6.3
CVSS
0.4%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MI
misskey · misskey-dev
>= 2024.5.0, < 2026.5.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48115
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48115
github.com
https://github.com/misskey-dev/misskey/releases/tag/2026.5.4
github.com
https://github.com/misskey-dev/misskey/security/advisories/GHSA-j49q-76hx-mv8f
More from misskey
9.3
CVE-2024-52591
Missing validation allows spoofed profiles and notes in Misskey
9.2
CVE-2026-46713
Misskey: JSON-LD signature validation + compaction may lead to improper activity handling
8.9
CVE-2026-47746
Misskey: JSON-LD signature validation + compaction is vulnerable to timing attacks
8.7
CVE-2026-103937
Misskey: Denial of service resulting from insufficient cleanup processing during file uploads
8.7
CVE-2026-104817
Misskey: Lack of rate limiting and size restrictions in RSS fetching API