CVE-2026-121621 is a high-severity (CVSS 8.8) OS Command Injection vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
A command injection vulnerability was found in Argo CD Image Updater, where a proxy URL configured on an SSH Git repository is passed unsanitized into a shell-interpreted SSH command.…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-121621.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Description
A command injection vulnerability was found in Argo CD Image Updater, where a proxy URL configured on an SSH Git repository is passed unsanitized into a shell-interpreted SSH command. An attacker able to set a malicious proxy value can inject shell metacharacters to execute arbitrary commands and access credentials in the context of the Image Updater process.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-121621. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-121621 in your dependencies?
Find it across your dependency tree, including transitive dependencies.