CVE-2026-82021

Hermes Agent 0.18.2 < 0.19.0 MCP Catalog Supply Chain RCE via Mutable Branch Reference

HIGH
8.3
CVSS Score
Published: August 28, 2026 at 06:50 PM UTC
Updated: September 8, 2026 at 08:39 PM UTC
1 product affected across 1 vendorHermes Agent

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Severity
HIGH8.3
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.18.2 ≤ v < 0.19.02026.7.7.2 ≤ v < 2026.7.200.18.22026.7.7.2
Affected range stops below 0.19.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 2026.7.20, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.3HIGHVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-494

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