{"cve":{"cve_id":"CVE-2026-73570","is_kev":true,"kev_date_added":"2026-08-21","kev_vendor_project":"Synacor","kev_product":"Zimbra Collaboration Suite (ZCS)","kev_vulnerability_name":"Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability","kev_short_description":"Zimbra Collaboration Suite (ZCS) contains an OS command injection vulnerability which could allow an unauthenticated attacker to send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.","kev_required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","kev_due_date":"2026-08-24","kev_known_ransomware":false,"kev_notes":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://blog.zimbra.com/2026/07/patch-release-update-zimbra-10-1-20/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-73570","kev_cwes":["CWE-78"],"epss_score":0.01506,"epss_percentile":0.72468,"epss_as_of":"2026-08-26","description":"A remote code execution vulnerability exists in Zimbra Collaboration (ZCS) before 10.1.20 when the optional zimbra-snmp package is installed and SNMP notifications are enabled. Due to improper sanitization of untrusted input during SNMP notification processing, an unauthenticated attacker can send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.","published_at":"2026-08-13T15:19:42.195000Z","last_modified_at":"2026-08-24T13:19:17.577000Z","cvss_v3_score":8.9,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"active","ssvc_automatable":false,"ssvc_technical_impact":"total","cwes":["CWE-78"],"nvd_references":["https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","https://wiki.zimbra.com/wiki/Security_Center"],"vuln_status":"Analyzed","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-08-13T16:21:52.865932Z","updated_at":"2026-08-24T19:35:50.286612Z"},"effective_severity":"HIGH","badges":["kev","poc","news"],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"L","value_label":"Low"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"synacor","vendor_name":"Synacor","product_slug":"zimbra-collaboration-suite","product_name":"zimbra_collaboration_suite","version_start":null,"version_start_inclusive":null,"version_end":"10.1.20","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*"},{"vendor_slug":"zimbra","vendor_name":"Zimbra","product_slug":"collaboration","product_name":"Collaboration","version_start":"0","version_start_inclusive":true,"version_end":"10.1.20","version_end_inclusive":false,"cpe23_uri":"cve5:zimbra:collaboration:0:10.1.20"}],"exploit_refs":[{"source":"nuclei","kind":"nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/network/cves/2026/CVE-2026-73570.yaml","title":"Zimbra Collaboration Suite < 10.1.20 - OS Command Injection","author":"0x_Akoko,ritikchaddha","disclosed_at":null}],"news":[{"id":1373,"source":"Dark Reading","url":"https://www.darkreading.com/vulnerabilities-threats/zimbra-flaw-exploitation-shrinking-window-patch","title":"Exploited Zimbra Flaw Highlights Shrinking Window to Patch","summary":"CISA has issued a three-day deadline for agencies to patch a Zimbra security vulnerability, CVE-2026-73570, which allows full takeover of a user's communications.","thumbnail_url":"https://eu-images.contentstack.com/v3/assets/blt6d90778a997de1cd/bltfa2c2aaf0a60b49e/6a8caeb8c3ca75471601b401/zimbra_OpturaDesign_shutterstock.jpg?width=720&quality=80&disable=upscale","author":"Jai Vijayan","published_at":"2026-08-24T21:46:55Z","fetched_at":"2026-08-24T22:34:20.693803Z","trending_score":0.45175077237392824,"cve_ids":["CVE-2026-73570"]},{"id":1313,"source":"The Hacker News","url":"https://thehackernews.com/2026/08/attackers-exploit-zimbra-snmp-flaw-for.html","title":"Attackers Exploit Zimbra SNMP Flaw for Unauthenticated Remote Code Execution","summary":"A now-patched security flaw impacting Zimbra Collaboration (ZCS) has come under active exploitation in the wild, according to the Polish Computer Emergency Response Team (CERT Polska).\n\nThe vulnerability in question is CVE-2026-73570 (CVSS score: 8.9), which refers to a case of command injection that can lead to remote code execution.\n\n\"A remote code execution vulnerability exists in Zimbra","thumbnail_url":"https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5vbtHH6C3JbT58Yghw2KNalqy-xoKLuJlsV9AGd_j2mQj4NKzVgWiOc9CDvUsT2JY0AchCk5140WhvNgZdKY2fwmeGEEi9FMvSSJvrBYVWndOKV9R47OEMZ59OOjv56DkPgpKo55fvHT7JSRW4yvh9_Xp5KBbw9xyJg2EGStHzg8ctloKfsJJPDLss1xR/s1600/zimbra.jpg","author":"info@thehackernews.com (The Hacker News)","published_at":"2026-08-20T13:24:28Z","fetched_at":"2026-08-20T14:25:27.873496Z","trending_score":0.1091714897603312,"cve_ids":["CVE-2026-73570"]}],"references":[{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://wiki.zimbra.com/wiki/Security_Center","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-08-13T15:19:42.195000Z","label":"CVE published","source":null},{"type":"first_article","at":"2026-08-20T13:24:28Z","label":"First news coverage","source":"The Hacker News"},{"type":"cisa_reported","at":"2026-08-21T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"ssvc_changed","at":"2026-08-21T18:43:27.515820Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"poc_available","at":"2026-08-26T17:38:11.388928Z","label":"Public PoC available","source":"nuclei"}]}