CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2025-54888
High (8.7). EPSS 0.6% chance of exploitation in the next 30 days. Fixed in @fedify/fedify 1.3.20, 1.4.13, 1.5.5.
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. In versions below 1.3.20, 1.4.0-dev.585 through 1.4.12, 1.5.0-dev.636 through 1.5.4, 1.6.0-dev.754 through 1.6.7, 1.7.0-pr.251.885 through 1.7.8 and 1.8.0-dev.909 through 1.8.4, an authentication bypass vulnerability allows any unauthenticated attacker to impersonate any ActivityPub actor by sending forged activities signed with their own keys. Activities are processed before verifying the signing key belongs to the claimed actor, enabling complete actor impersonation across all Fedify instances. This is fixed in versions 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9 and 1.8.5.
Severity
- EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 51% of CVEs (scores of 2026-11-01)
- CWEs
- CWE-287, CWE-863
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | <1.3.20 | 1.3.20 |
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | >=1.4.0-dev.585 <1.4.13 | 1.4.13 |
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | >=1.5.0-dev.636 <1.5.5 | 1.5.5 |
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | >=1.6.0-dev.754 <1.6.8 | 1.6.8 |
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | >=1.7.0-pr.251.885 <1.7.9 | 1.7.9 |
| GHSA-6jcc-xgcr-q3h4 | npm | @fedify/fedify | >=1.8.0-dev.909 <1.8.5 | 1.8.5 |