CVE-2026-90679 (GCVE-0-2026-90679)

Vulnerability from cvelistv5 – Published: 2026-09-13 03:55 – Updated: 2026-09-15 17:17 X_Open Source
VLAI
Summary
Forgejo 13.0.0 through 16.0.4, when "[federation] ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belonging to the actor named in the activity body. The signature verification in routers/api/v1/activitypub/reqsignature.go validates the request signature, but the inbox activity handlers subsequently read the acting identity from the attacker-controlled JSON body without binding it to the verified signing key. Additionally, the signed Digest header is not recomputed against the received request body. A remote attacker who hosts a single valid ActivityPub actor and keypair can therefore submit signature-valid activities attributed to any actor identity they name.
Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-15 17:17 UTC
CWE
  • CWE-348 - Use of Less Trusted Source
Assigner
mitre CNA under the mitre root
CNA scorecard E 28/100 over 2260 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Forgejo Forgejo Affected: 13.0.0 , ≤ 16.0.4 (semver)
    cpe:2.3:a:forgejo:forgejo:*:*:*:*:*:*:*:*
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