CVE-2026-55797: Argo CD repo-server command injection via crafted SSH repository SOCKS5 proxy URL

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.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.5%, percentile 75: FIRST’s model estimates a 1.5% chance of exploitation activity in the next 30 days, higher than 75% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Editorial verdict: Patch this week. Argo CD: Repo-Server RCE and AppProject Bypass (Oct 2026) — Upgrade Argo CD to a patched 3.3, 3.4 or 3.5 release this week, and today on shared instances where people you do not fully trust can push to tracked repos or merely view an Application.

What it is

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 2.11.0 until 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2, the Argo CD repo-server is vulnerable to command injection when it clones, tests, or fetches an SSH Git repository configured with a proxy URL. The proxy host and port are embedded in an SSH ProxyCommand that is executed through a shell without neutralizing shell metacharacters. A user who can create or update a repository or repository credential template can supply a crafted proxy host to execute commands in the repo-server and access its Git, Helm, and OCI credentials. This issue is fixed in versions 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2.

Weakness type: CWE-78.

Product: argoproj argo-cd · Assigned by: GitHub_M · Published: 2026-10-09

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: unchanged

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 none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.55% probability of exploitation activity in the next 30 days; percentile 75.

Timeline

• 2026-10-07 — erroneo.us brief: Argo CD: Repo-Server RCE and AppProject Bypass (Oct 2026)
• 2026-10-09 — CVE record last updated
• 2026-10-09 — CVE record published by GitHub_M

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. CVE.org record CVE-2026-55797 cve.org
2. NVD entry CVE-2026-55797 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
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