Misskey: JSON-LD signature validation + compaction may lead to improper activity handling
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.2epss 0.2%
exploitation probability
0.2%top 93% of all CVEs
observed exploitation
nono source reports it
Misskey is an open source, federated social media platform. Versions 12.37.0 and later, but prior to 2026.5.4, contain a vulnerability in the JSON-LD signature validation and compaction process that allows spoofed activities to be accepted as valid. This issue has been fixed in version 2026.5.4.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:H/SA:N
Affected products
misskey-dev · misskey