Security Digest · Vulnerability record
CVE-2026-71963: Hermes Agent 0.18.2 - 0.21.0 RCE via git core.fsmonitor Config Injection
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.
CVSS 8.6 High EPSS 0.9% · p58 Patch this week
Should you act?
Normal patch cycle
No exploitation signal; fix it in your next routine update if you are affected. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9%, percentile 58: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 58% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Editorial verdict: Patch this week. GitSpawn: Repo Git Config Runs Code in AI Coding Agents — Update your coding agents this week and never point one at a repository that arrived as files until you have read its .git/config; ordinary clones are not affected, and no attacks have been reported.
What it is
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 type: CWE-78.
Product: NousResearch hermes-agent · Assigned by: VulnCheck · Published: 2026-09-03
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| NousResearch | hermes-agent | 0.18.2 <= 0.21.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheck | 4.0 | 8.6 High | 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 |
| VulnCheck | 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: active
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.86% probability of exploitation activity in the next 30 days; percentile 58.
Timeline
- — erroneo.us brief: GitSpawn: Repo Git Config Runs Code in AI Coding Agents
- — CVE record last updated
- — CVE record published by VulnCheck
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Patch Commit github.com
Vulnerability records
- CVE.org record CVE-2026-71963 cve.org
- NVD entry CVE-2026-71963 nvd.nist.gov
Other references from the CVE record and advisory
- Manifold Blog manifold.security
- Pull Request github.com
- vulncheck.com vulncheck.com