CVE-2026-82021
HIGHDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
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CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 13% of all known CVEs.
References
Related Vulnerabilities
Other CWE-494 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-5398 | High | 7.5 | 88% | - | Fix |
| CVE-2022-40799 | High | 8.8 | 32% | KEV | - |
| CVE-2026-3502 | High | 7.8 | 5.7% | KEV | Fix |
| CVE-2018-19234 | High | 8.8 | 3.3% | - | Fix |
| CVE-2016-6567 | Critical | 9.8 | 2.9% | - | - |
| CVE-2016-6564 | High | 8.1 | 2.7% | - | - |
Common questions
How do I fix CVE-2026-82021?
No published fix for CVE-2026-82021 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-82021 being actively exploited?
Not that we know of. CVE-2026-82021 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.23% is the estimated probability that it will be exploited in the next 30 days. That is higher than 13% of all scored CVEs.
How severe is CVE-2026-82021?
CVE-2026-82021 has a CVSS v3 base score of 8.3, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2026-82021
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-28.