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Tools AI Risk Radar ai-incident-0019

Incident record

Hermes Agent shipped an MCP catalogue pinned to a branch instead of a commit

Severity
Critical
Status
Patched
Type
Poisoning
Target
Hermes Agent 0.18.2 up to 0.19.0
Actor
researcher
CVE
CVE-2026-82021

What happened

Hermes Agent referenced a third-party upstream repository in its bundled MCP catalogue by mutable branch pointer rather than a pinned commit. Anyone who compromised that upstream could push code to every host that had installed the catalogue entry, with no action needed from the operator.

Classified CWE-494, download of code without integrity check. CVSS 3.1 scores it 8.3 high and CVSS 4.0 scores it 9.0 critical. A branch reference is a promise that whoever controls the branch controls your machine later, which is the same supply-chain shape as the npm worm already on this board, arriving through an agent tool catalogue instead.

Sources

One record from the AI Risk Radar, maintained by the Security Desk. Data: CSV · JSON ·RSS · CC BY 4.0 with attribution to YFarmX.Tracker updated · 18 September 2026