n8n, an open-source workflow automation platform, has recently issued a critical security alert regarding a high-severity vulnerability that could enable authenticated remote code execution (RCE). The flaw, assigned the CVE identifier CVE-2026-21877, has a CVSS score of 10.0, indicating its potential for significant impact. This vulnerability affects both self-hosted and cloud versions of n8n, making it a pressing concern for a wide range of users. If exploited, it could allow an authenticated user to execute untrusted code on the n8n service, potentially leading to a full compromise of the affected instance. The issue has been addressed in version 1.121.3, released in November 2025, with security researcher Théo Lelasseux credited for discovering and reporting the flaw. Users are strongly advised to upgrade to this version or later to mitigate the risk. In the meantime, administrators can limit exposure by disabling the Git node and restricting access for untrusted users. This alert comes on the heels of n8n addressing a series of critical flaws, including CVE-2025-68613 and CVE-2025-68668, which also had the potential for code execution under specific conditions. These recent incidents highlight the ongoing need for vigilance and proactive security measures in the face of evolving threats.
