Is CVE-2026-9353 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-9353 being exploited in the wild.

How severe is CVE-2026-9353?

High severity, with a CVSS score of 7.3, published 24 May 2026.

Which products and versions are affected?

NousResearch Hermes Agent < 0.15.0; hermes-agent (PyPI) ECOSYSTEM:introduced=0,fixed=0.15.0.

Is there a fix for CVE-2026-9353?

Yes. hermes-agent (PyPI): upgrade to 0.15.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-9353 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-9353?

Check whether you run NousResearch Hermes Agent or hermes-agent (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-9353: NousResearch hermes-agent prompt injection bypass in Skills Guard

Q: Is there a fix for CVE-2026-9353?

Yes. hermes-agent (PyPI): upgrade to 0.15.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-9353 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-9353?

Check whether you run NousResearch Hermes Agent or hermes-agent (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-9353 · Severity: high · CVSS 7.3 · Published 2026-05-24

NousResearch hermes-agent is a tool used for managing AI agent skills and behaviors. A vulnerability in its security filtering component allows attackers to bypass safety checks by slightly modifying malicious commands, such as inserting extra words into a prompt. This could allow an attacker to install malicious skills that override the agent's core instructions, potentially leading to unauthorized actions or data manipulation without the user's knowledge.

Technologies: NousResearch Hermes Agent, hermes-agent (PyPI). Vendors: NousResearch, PyPI.

Quick answers

Is CVE-2026-9353 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-9353 being exploited in the wild.
How severe is CVE-2026-9353?: High severity, with a CVSS score of 7.3, published 24 May 2026.
Which products and versions are affected?: NousResearch Hermes Agent < 0.15.0; hermes-agent (PyPI) ECOSYSTEM:introduced=0,fixed=0.15.0.
Is there a fix for CVE-2026-9353?: Yes. hermes-agent (PyPI): upgrade to 0.15.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-9353 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-9353?: Check whether you run NousResearch Hermes Agent or hermes-agent (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

hermes-agent (PyPI): upgrade to 0.15.0 or later
```
pip install "hermes-agent>=0.15.0"
```

Technical details

A prompt injection vulnerability exists in the Skills Guard Multi-Word Prompt Handler within `agent/skills_guard.py`. The root cause is the use of rigid regular expressions for the `THREAT_PATTERNS` argument, specifically for patterns like 'system prompt override'. Because these patterns do not account for flexible whitespace or intervening words, an attacker can bypass the filter by injecting extraneous words (e.g., 'system prompt temporary override'). This bypass allows the installation of malicious skills that can override system prompts and alter agent behavior. The issue is addressed in version 0.15.0 by implementing more flexible regex matching.

Affected products

NousResearch hermes-agent < 0.15.0

Identifiers

CVE-2026-9353
GHSA-238w-f66p-w349
PYSEC-2026-2509

Timeline

2026-04-24: disclosed: Public disclosure via GitHub Gist and PoC release
2026-05-24: advisory: NVD publication date
2026-05-26: advisory: GitHub Advisory published
2026-06-30: patched: GitHub Advisory updated with patch information

References

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