Vulnerability · Published May 24, 2026 · Assigned by VulDB

CVE-2026-9366NousResearch hermes-agent prompt_builder.py _scan_context_content injection

High 7.3

In plain English

A high-severity injection in hermes-agent from NousResearch. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.3High

Exploit odds (30 days)0.3%top 76.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

A vulnerability was found in NousResearch hermes-agent 2026.4.23. The impacted element is the function _scan_context_content of the file agent/prompt_builder.py. The manipulation results in injection. The attack may be performed from remote. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	hermes-agent	0.15.0	GHSA-pgp4-xr4j-h5cg
PyPI	hermes-agent	0.15.0	PYSEC-2026-2514

Affected products (as reported)

Vendor	Product	Versions
NousResearch	hermes-agent	2026.4.23

Weakness: CWE-74, CWE-707 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R

References

VDB-365329 | NousResearch hermes-agent prompt_builder.py _scan_context_content injection vdb-entry, technical-description
VDB-365329 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
Submit #812227 | NousResearch hermes-agent 2026.4.23 Injection (CWE-74) third-party-advisory
https://gist.github.com/YLChen-007/581fd92de5548fbaacb2092e848a75cc exploit