CVE-2025-66626: argoproj/argo-workflows is vulnerable to RCE via ZipSlip and symbolic links
Summary The patch deployed against CVE-2025-62156 is ineffective against malicious archives containing symbolic links.
Details The untar code that handles symbolic links in archives is unsafe. Concretely, the computation of the link's target and the subsequent check are flawed: https://github.com/argoproj/argo-workflows/blob/5291e0b01f94ba864f96f795bb500f2cfc5ad799/workflow/executor/executor.go#L1034-L1037
PoC 1. Create a malicious archive containing two files: a symbolik link with path "./work/foo" and target "/etc", and a normal text file with path "./work/foo/hostname". 2. Deploy a workflow like the one in https://github.com/argoproj/argo-workflows/security/advisories/GHSA-p84v-gxvw-73pf with the malicious archive mounted at /work/tmp. 3. Submit the workflow and wait for its execution. 4. Connect to the corresponding pod and observe that the file "/etc/hostname" was altered by the untar operation performed on the malicious archive. The attacker can hence alter arbitrary files in this way.
Impact The attacker can overwrite the file /var/run/argo/argoexec with a script of their choice, which will be executed at the pod's start.
Other sources
Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Versions 3.6.13 and below and versions 3.7.0 through 3.7.4, contain unsafe untar code that handles symbolic links in archives. Concretely, the computation of a link's target and the subsequent check are flawed. An attacker can overwrite the file /var/run/argo/argoexec with a script of their choice, which would be executed at the pod's start. The patch deployed against CVE-2025-62156 is ineffective against malicious archives containing symbolic links. This issue is fixed in versions 3.6.14 and 3.7.5.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-66626?
CVE-2025-66626 has a high severity due to its potential to exploit symbolic links in archives.
How do I fix CVE-2025-66626?
To fix CVE-2025-66626, upgrade to version 3.6.14 or higher of the Argo Workflows package.
What versions of Argo Workflows are affected by CVE-2025-66626?
CVE-2025-66626 affects Argo Workflows versions up to 2.5.3-rc4 and versions between 3.7.0 and 3.7.5.
Can CVE-2025-66626 be exploited remotely?
Yes, CVE-2025-66626 can be exploited remotely if an attacker tricks a user into processing a malicious archive with symbolic links.
What is the recommended remediation for CVE-2025-66626?
The recommended remediation for CVE-2025-66626 is to apply patches provided in the latest versions of the affected Argo Workflows packages.