{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-39910: STACKIT IaaS API Privilege Escalation via Service Account Attachment","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-39910","status":"final","version":"1","initial_release_date":"2026-06-08T16:16:09.469Z","current_release_date":"2026-06-09T15:47:16.803Z","revision_history":[{"date":"2026-06-08T16:16:09.469Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"STACKIT IaaS API contains a missing authorization check vulnerability that allows authenticated, low-privileged attackers to escalate privileges to full organization compromise by attaching arbitrary service accounts to virtual machines they control. Attackers can exploit the unvalidated PUT servers service-accounts endpoint to attach high-privileged service accounts and query the Instance Metadata Service to retrieve OAuth2 tokens, bypassing tenant boundaries and gaining unauthorized control over the entire organization environment.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-39910 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-39910"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-39910"},{"category":"external","summary":"status.stackit.cloud","url":"https://status.stackit.cloud"},{"category":"external","summary":"vulncheck.com","url":"https://www.vulncheck.com/advisories/stackit-iaas-api-privilege-escalation-via-service-account-attachment"}]},"product_tree":{"branches":[{"category":"vendor","name":"STACKIT","branches":[{"category":"product_name","name":"IaaS API","branches":[{"category":"product_version_range","name":"<2026-05-28","product":{"name":"STACKIT IaaS API <2026-05-28","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:stackit:iaas_api:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-39910","title":"STACKIT IaaS API Privilege Escalation via Service Account Attachment","notes":[{"category":"description","text":"STACKIT IaaS API contains a missing authorization check vulnerability that allows authenticated, low-privileged attackers to escalate privileges to full organization compromise by attaching arbitrary service accounts to virtual machines they control. Attackers can exploit the unvalidated PUT servers service-accounts endpoint to attach high-privileged service accounts and query the Instance Metadata Service to retrieve OAuth2 tokens, bypassing tenant boundaries and gaining unauthorized control over the entire organization environment.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","baseScore":9.3,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 2026-05-28.","product_ids":["CSAFPID-1"]}]}]}