Description
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.
Severity (CVSS)
| Base score | 8.9 |
|---|---|
| Severity | High |
| Version | CVSS 4.0 |
| Vector | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N |
| Provided by | CNA |
Weaknesses
- CWE-367 — CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
Affected products
| Vendor | Product | Versions |
|---|---|---|
| misskey-dev | misskey | >= 12.37.0, < 2026.5.4 |
References
- https://github.com/misskey-dev/misskey/security/advisories/GHSA-38jx-423m-g387 (x_refsource_CONFIRM)
- https://github.com/misskey-dev/misskey/releases/tag/2026.5.4 (x_refsource_MISC)
Generated from the official CVE List on 04 Aug 2026 07:02 UTC.