CVE-2026-82021

Hermes Agent 0.18.2 prior to 0.19.0 contains a supply chain vulnerability in its bundled MCP catalog that allows a remote attacker to execute arbitrary code by compromising a third-party upstream repository referenced via a mutable branch rather than a pinned commit SHA. An attacker who compromises the upstream repository can propagate malicious code to every host that installs the affected catalog entry, with no further action required by the operator.

Scoring

Severity
CRITICAL
CVSS base score
9
CVSS vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
EPSS probability
0.23%
CWE
CWE-494
Published
2026-08-28
Last modified
2026-08-31

Affected products

Weakness type

Related vulnerabilities

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