CVE Catalog

CVE-2026-9354

MediumCVSS 6.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

26th percentile - higher than 26% of all known CVEs

Summary

Vulnerability due to improper output escaping in the format_message function in Slack Agent/Mattermost Agent in hermes-agent. Manipulation of the format_message argument allows code injection.

Risk Assessment

A remote attacker can inject malicious code, potentially leading to script execution or data theft.

Recommendation

Implement proper output escaping for the format_message argument and consider using Content Security Policy.

Other vulnerabilities in hermes-agent

See all
Original NVD description (English source)

A vulnerability was detected in NousResearch hermes-agent up to 2026.4.16. The affected element is an unknown function of the component Slack Agent/Mattermost Agent. The manipulation of the argument format_message results in escaping of output. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS