# CVE-2026-71963: Hermes Agent 0.18.2 - 0.21.0 RCE via git core.fsmonitor Config Injection

> Attackers can execute arbitrary OS commands and steal API keys by tricking users into opening a malicious repository with a crafted git config.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Sep 2026
- **Updated:** 3 Sep 2026
- **Also known as:** GHSA-cc88-9pxf-j2wv

## What is CVE-2026-71963?

CVE-2026-71963 is a high-severity command injection vulnerability in NousResearch hermes-agent, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Hermes Agent 0.18.2 through 0.21.0, fixed in commit f6234d0, contains a remote code execution vulnerability that allows attackers to execute arbitrary OS commands by supplying a malicious repository with a crafted .git/config that sets core.fsmonitor to an attacker-controlled command. When a user opens the malicious repository and sends any message, the agent triggers a git status index refresh which executes the injected command in the user's process context, exposing the full environment including configured provider API keys.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-71963?


## How do I fix CVE-2026-71963?

No fix has been published for CVE-2026-71963 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71963 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-71963 exists.

Public exploit code:

- CVE-2026-71963 - Hermes Agent 0.18.2-0.21.0 RCE via a repository-delivered .git/config (core.fsmonitor). Stdlib-only Python, verified on real 0.21.0 with a clean negative control on the fixed build. (github_poc): https://github.com/Boreas37/CVE-2026-71963-PoC

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71963 and fix it if it is affected.

What it is: CVE-2026-71963 is a high-severity command injection vulnerability in NousResearch hermes-agent, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-71963 exists.

Affected product: NousResearch hermes-agent. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-71963/ (Markdown: https://insights.sbomify.com/CVE-2026-71963/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71963
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71963
- OSV: https://osv.dev/vulnerability/CVE-2026-71963

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-71963/
Summaries are generated and may contain mistakes; the official description above is the record.