Argo Workflows CVE-2025-62156

Exploitation requires an attacker able to submit or run an Argo Workflow and control the contents of an artifact that the workflow extracts (e.g., a tar.gz/zip placed in an artifact repository such as S3), so the attack surface is authenticated workflow users - most impactful in multi-tenant clusters. The vulnerable path is the executor's untar/unpack logic in workflow/executor/executor.go, which uses filepath.Join(dest, filepath.Clean(header.Name)) without verifying the result stays under the extraction directory, allowing traversal/absolute entries to write into system paths like /etc. Limiting factors: affected only in versions prior to 3.6.12 and 3.7.0 through 3.7.2; requires the attacker to control archive contents and have workflow-submission (low) privileges; impact is confined to the affected container (Scope:Unchanged) though overwriting /etc/passwd, /etc/hosts, or /etc/crontab can enable privilege escalation or persistence within it.

All signals point to a credible but conditional threat rather than an internet-wide emergency. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, 8.8) indicates a network-reachable, low-complexity attack requiring low privileges and no user interaction, with full confidentiality/integrity/availability impact scoped to the affected container. The PR:L metric is the key limiter: an attacker must already be an authenticated low-privileged user of Argo Workflows able to submit a workflow and control an artifact source - this is not an anonymous remote exploit. Publicly available exploit code exists (detailed PoC in the GHSA advisory), which raises practical risk, but EPSS is only 0.59% (47th percentile) and there is no CISA KEV listing, so there is no evidence of active, widespread exploitation. The low EPSS alongside a working PoC is consistent with a vulnerability that is realistic to exploit in targeted scenarios (multi-tenant Argo clusters) but has not seen mass automated attacks. Net: a real priority for organizations running multi-tenant Argo Workflows, but the authentication prerequisite and lack of KEV status mean it should be patched promptly rather than treated as an emergency zero-day.

A low-privileged tenant on a shared Argo Workflows cluster crafts a malicious tar.gz whose entries use path-traversal names such as '../../../../etc/crontab', uploads it to an artifact repository (e.g., S3), and submits a workflow that extracts the artifact into /work/tmp. The vulnerable untar logic resolves the entry outside the extraction directory and writes into the container's /etc, overwriting /etc/passwd or /etc/crontab to escalate privileges or establish persistence. A detailed public PoC demonstrating this exact technique is published in the GHSA advisory.