{"id":"CVE-2026-121621","title":"Github.com/argoproj-labs/argocd-image-updater: argocd-image-updater: arbitrary command execution via crafted ssh repository proxy configuration","summary":"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 i…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-78"],"vendor":"Red Hat","product":"argocd-image-updater","affected":["argocd-image-updater < 1.4.1","openshift-gitops-1/argocd-image-updater-rhel9 (all versions)","openshift-gitops-1/gitops-rhel9-operator"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-11-05T04:56:48.478664Z"},"published":"2026-11-03","updated":"2026-11-06","sourceUpdated":"2026-11-06T05:31:44.592Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-121621","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-121621"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2565914","label":"RHBZ#2565914"},{"url":"https://github.com/argoproj-labs/argocd-image-updater/pull/1905"},{"url":"https://redhat.atlassian.net/browse/GITOPS-11907"}],"tags":["cve.org"],"epss":0.01762,"epssPercentile":0.78103,"ingestedAt":"2026-11-05T21:36:00.891Z","slug":"CVE-2026-121621","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `argocd-image-updater < 1.4.1`\n- `openshift-gitops-1/argocd-image-updater-rhel9 (all versions)`\n- `openshift-gitops-1/gitops-rhel9-operator`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\n--- CME Mitigation Guidance (2026-11-04) ---\nDisclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.\n\nThe highest-value action is to eliminate shell evaluation of GIT_SSH_COMMAND and strictly validate proxy host inputs in Argo CD Image Updater: upgrade to the fixed Openshift Gitops 1/Argocd Image Updater Rhel builds, which validate the proxy URL scheme, hostname, and port and write proxy execution settings to a temporary wrapper script instead of embedding them directly into GIT_SSH_COMMAND, closing all 3 injection vectors (crafted proxy hostname containing shell metacharacters in repository configuration, crafted proxy URL in repository credential templates, crafted proxy configuration in backing repository Secrets). Until patched, this is only a concern on Argo CD Image Updater deployments cloning or fetching Git repositories over SSH configured with a proxy — HTTPS Git repository connections are unaffected — so restrict and audit access for creating or updating repositories, repository credential templates, and backing repository Secrets. As a compensating measure, sanitize metacharacters and argument delimiters in repository proxy parameters before passing them to SSH, run SELinux in enforcing mode to confine the Argo CD process and restrict arbitrary command execution, deploy an EDR agent to monitor and detect anomalous child shell spawns originating from the Image Updater service, and use Falco or eBPF runtime probes to detect unexpected shell execution and anomalous network or file activity. These controls limit blast radius and contain exploitation, but they do not fix the underlying command injection flaw — apply the upstream patch to fully remediate.\n\nHighest-impact CME: CME-1307 Command Injection Prevention (No Shell Invocation) (high)","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.4,"exploitation":0,"ransomware":0},"changes":[]}