CVE-2026-47746 — Misskey: JSON-LD signature validation + compaction is vulnerable to timing attacks
Misskey is an open source, federated social media platform. Versions 12.37.0 and later, but prior to 2026.5.4, are vulnerable to timing attacks during JSON-LD signature validati…
Published: 2026-08-03 · CVSS: 8.9 · CVSS 4.0
Misskey is an open source, federated social media platform. Versions 12.37.0 and later, but prior to 2026.5.4, are vulnerable to timing attacks during JSON-LD signature validation and the compaction process. Because the JSON-LD parsing context is not shared between signature verification and subsequent processing, the application may trust information that should not be trusted, resulting in a time-of-check to time-of-use (TOCTOU) flaw. This allows an attacker to have fraudulent activities accepted as valid, leading to a loss of integrity. This issue has been fixed in version 2026.5.4.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7