NousResearch hermes-agent Skills Guard Multi-Word Prompt skills_guard.py injection
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
A security vulnerability has been detected in NousResearch hermes-agent up to 2026.4.23. Impacted is an unknown function of the file agent/skills_guard.py of the component Skills Guard Multi-Word Prompt Handler. The manipulation of the argument THREAT_PATTERNS leads to injection. Remote exploitation of the attack is possible. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| NousResearch | hermes-agent | 2026.4.0; 2026.4.1; 2026.4.2; 2026.4.3; 2026.4.4; 2026.4.5; 2026.4.6; 2026.4.7; 2026.4.8; 2026.4.9; 2026.4.10; 2026.4.11; 2026.4.12; 2026.4.13; 2026.4.14; 2026.4.15; 2026.4.16; 2026.4.17; 2026.4.18; 2026.4.19; 2026.4.20; 2026.4.21; 2026.4.22; 2026.4.23 | — | No fix listed | CNA |
| — | hermes-agent (PyPI) | before 0.15.0 | 0.15.0 | Patch available | GHSA-238w-f66p-w349 |
- hermes-agent VendorNousResearch Affected 2026.4.0; 2026.4.1; 2026.4.2; 2026.4.3; 2026.4.4; 2026.4.5; 2026.4.6; 2026.4.7; 2026.4.8; 2026.4.9; 2026.4.10; 2026.4.11; 2026.4.12; 2026.4.13; 2026.4.14; 2026.4.15; 2026.4.16; 2026.4.17; 2026.4.18; 2026.4.19; 2026.4.20; 2026.4.21; 2026.4.22; 2026.4.23 Fixed in — No fix listed CNA
- hermes-agent (PyPI) Vendor— Affected before 0.15.0 Fixed in 0.15.0 Patch available GHSA-238w-f66p-w349
CPE names CNA · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:* | — | — | NousResearch |
- cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:* Versions — — ·NousResearch
Remediation
- Fix · GHSA-238w-f66p-w349 hermes-agent (PyPI) Fixed in 0.15.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-9353
- 2026-10-03 Alias added: GHSA-238w-f66p-w349
References
More NousResearch vulnerabilities
- TI-2026-50258 Hermes Agent 0.18.2 - 0.21.0 RCE via git core.fsmonitor Config Injection CVSS 4.0HIGH 8.6
- TI-2026-12325 NousResearch hermes-agent Live Webhook Endpoint base.py extract_media path traversal CVSS 4.0MEDIUM 6.9
- TI-2026-08962 NousResearch hermes-agent Webhook Endpoint feishu.py _handle_webhook_request resource consumption CVSS 4.0MEDIUM 6.9
- TI-2026-08959 NousResearch hermes-agent run_agent.py _compress_context injection CVSS 4.0MEDIUM 6.9
- TI-2026-08958 NousResearch hermes-agent skills_tool.py skill_view injection CVSS 4.0MEDIUM 6.9
- TI-2026-08218 NousResearch hermes-agent Environment Variable code_execution_tool.py execute_code sandbox CVSS 4.0MEDIUM 6.9
Sources
- CVE-2026-9353 · CVE Program
- CVE-2026-9353 · NVD
- FIRST EPSS
- GHSA-238w-f66p-w349 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences