CVE-2026-71963
RCE via malicious .git/config core.fsmonitor injection in Hermes Agent 0.18.2–0.21.0
Is CVE-2026-71963 being exploited?
Not confirmed. CVE-2026-71963 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.86% probability of exploitation in the next 30 days.
How severe is CVE-2026-71963?
CVE-2026-71963 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-71963?
Yes. A fix has been recorded for CVE-2026-71963. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-71963 affect?
CVE-2026-71963 affects Hermes Agent 0.18.2 - 0.21.0, Developer/workstation instances running Hermes Agent. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-71963?
Update to commit f6234d0 or later, do not open untrusted repos, rotate exposed API keys.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution: crafted .git/config sets core.fsmonitor to run OS commands in the user's agent process, allowing command execution and exfiltration of env and API keys.
Immediate action required
- affected>= 0.18.2 and <= 0.21.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.