CVE-2026-73570

CRITICALPre-NVD 8.99.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-08-21), indicating real-world exploitation has been confirmed by US federal agencies. A secondary CVSS source baseline 8.9 retained for reference (NVD's own analysis pending). Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, secondary
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 12%CVSS: 8.9Exploit: cisa kev · ssvc active · epss top5pct · public exploitExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

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.

CVSS v3
8.9
EG Score
9.0CRITICALhigh confidence
EG Risk
81
EG Risk 81/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Attend at medium and Act at high mission impact.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact, and watch the vendor's advisory for the fix.
EPSS PROB
12%
EPSS %ILE
95th
KEV
⚠ Exploited

CISA SSVCTrack at low, Attend at medium and Act at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact, and watch the vendor's advisory for the fix.

Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 13, 2026

Last Modified

August 24, 2026

Advisory Details (2)

Auto-updated Aug 13, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Security Center - Zimbra :: Tech Center

https://wiki.zimbra.com/wiki/Security_Center
generic

Zimbra Security Advisories - Zimbra :: Tech Center

https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Vendor Advisories for CVE-2026-73570(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 58× in last 7d / 248× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 424 total refreshes for this CVE.

  1. 2026-10-05 10:53 UTCGHSA enrichment
  2. 2026-10-05 07:05 UTCGHSA enrichment
  3. 2026-10-05 03:17 UTCGHSA enrichment
  4. 2026-10-04 23:28 UTCGHSA enrichment
  5. 2026-10-04 19:41 UTCGHSA enrichment
  6. 2026-10-04 15:53 UTCGHSA enrichment
  7. 2026-10-04 12:02 UTCGHSA enrichment
  8. 2026-10-04 08:15 UTCGHSA enrichment
  9. 2026-10-04 04:27 UTCGHSA enrichment
  10. 2026-10-04 00:39 UTCGHSA enrichment
  11. 2026-10-03 20:51 UTCGHSA enrichment
  12. 2026-10-03 17:04 UTCEG score recompute
  13. 2026-10-03 17:03 UTCGHSA enrichment
  14. 2026-10-03 14:26 UTCEPSS rescore
  15. 2026-10-03 13:16 UTCGHSA enrichment
  16. 2026-10-03 09:28 UTCGHSA enrichment
  17. 2026-10-03 05:39 UTCGHSA enrichment
  18. 2026-10-03 01:51 UTCGHSA enrichment
  19. 2026-10-02 22:03 UTCGHSA enrichment
  20. 2026-10-02 18:14 UTCEG score recompute
  21. 2026-10-02 18:14 UTCGHSA enrichment
  22. 2026-10-02 18:14 UTCGHSA enrichment
  23. 2026-10-02 18:14 UTCGHSA enrichment
  24. 2026-10-02 14:26 UTCGHSA enrichment
  25. 2026-10-02 10:36 UTCGHSA enrichment
Show 75 more
  1. 2026-10-02 06:45 UTCGHSA enrichment
  2. 2026-10-02 02:57 UTCGHSA enrichment
  3. 2026-10-01 23:09 UTCEG score recompute
  4. 2026-10-01 23:09 UTCGHSA enrichment
  5. 2026-10-01 19:50 UTCEPSS rescore
  6. 2026-10-01 19:21 UTCGHSA enrichment
  7. 2026-10-01 15:32 UTCGHSA enrichment
  8. 2026-10-01 11:44 UTCGHSA enrichment
  9. 2026-10-01 07:56 UTCGHSA enrichment
  10. 2026-10-01 04:08 UTCGHSA enrichment
  11. 2026-10-01 00:20 UTCGHSA enrichment
  12. 2026-09-30 20:31 UTCGHSA enrichment
  13. 2026-09-30 16:44 UTCEG score recompute
  14. 2026-09-30 16:44 UTCGHSA enrichment
  15. 2026-09-30 12:56 UTCGHSA enrichment
  16. 2026-09-30 09:06 UTCGHSA enrichment
  17. 2026-09-30 05:17 UTCGHSA enrichment
  18. 2026-09-30 01:27 UTCGHSA enrichment
  19. 2026-09-29 21:40 UTCGHSA enrichment
  20. 2026-09-29 17:52 UTCEG score recompute
  21. 2026-09-29 17:51 UTCGHSA enrichment
  22. 2026-09-29 15:24 UTCEPSS rescore
  23. 2026-09-29 14:01 UTCGHSA enrichment
  24. 2026-09-29 10:13 UTCGHSA enrichment
  25. 2026-09-29 06:24 UTCGHSA enrichment
  26. 2026-09-29 02:37 UTCGHSA enrichment
  27. 2026-09-28 22:49 UTCEG score recompute
  28. 2026-09-28 22:49 UTCGHSA enrichment
  29. 2026-09-28 19:01 UTCGHSA enrichment
  30. 2026-09-28 15:12 UTCEG score recompute
  31. 2026-09-28 15:12 UTCGHSA enrichment
  32. 2026-09-28 13:52 UTCEPSS rescore
  33. 2026-09-28 11:24 UTCGHSA enrichment
  34. 2026-09-28 07:36 UTCGHSA enrichment
  35. 2026-09-28 03:48 UTCGHSA enrichment
  36. 2026-09-28 00:00 UTCGHSA enrichment
  37. 2026-09-27 21:51 UTCCISA KEV update
  38. 2026-09-27 20:12 UTCGHSA enrichment
  39. 2026-09-27 16:24 UTCEG score recompute
  40. 2026-09-27 16:24 UTCGHSA enrichment
  41. 2026-09-27 13:48 UTCEPSS rescore
  42. 2026-09-27 12:37 UTCGHSA enrichment
  43. 2026-09-27 08:49 UTCGHSA enrichment
  44. 2026-09-27 05:01 UTCGHSA enrichment
  45. 2026-09-27 01:12 UTCGHSA enrichment
  46. 2026-09-26 21:22 UTCGHSA enrichment
  47. 2026-09-26 17:33 UTCEG score recompute
  48. 2026-09-26 17:33 UTCGHSA enrichment
  49. 2026-09-26 15:59 UTCEPSS rescore
  50. 2026-09-26 13:43 UTCGHSA enrichment
  51. 2026-09-26 09:54 UTCGHSA enrichment
  52. 2026-09-26 06:05 UTCGHSA enrichment
  53. 2026-09-26 02:17 UTCEG score recompute
  54. 2026-09-26 02:17 UTCGHSA enrichment
  55. 2026-09-25 22:27 UTCGHSA enrichment
  56. 2026-09-25 19:35 UTCCISA KEV update
  57. 2026-09-25 18:37 UTCGHSA enrichment
  58. 2026-09-25 14:55 UTCCISA KEV update
  59. 2026-09-25 14:49 UTCGHSA enrichment
  60. 2026-09-25 11:01 UTCGHSA enrichment
  61. 2026-09-25 07:13 UTCGHSA enrichment
  62. 2026-09-25 03:25 UTCGHSA enrichment
  63. 2026-09-24 23:38 UTCGHSA enrichment
  64. 2026-09-24 19:50 UTCGHSA enrichment
  65. 2026-09-24 19:31 UTCCISA KEV update
  66. 2026-09-24 16:02 UTCEG score recompute
  67. 2026-09-24 16:02 UTCGHSA enrichment
  68. 2026-09-24 12:15 UTCGHSA enrichment
  69. 2026-09-24 08:27 UTCGHSA enrichment
  70. 2026-09-24 04:39 UTCGHSA enrichment
  71. 2026-09-24 00:51 UTCGHSA enrichment
  72. 2026-09-23 21:04 UTCEG score recompute
  73. 2026-09-23 21:04 UTCGHSA enrichment
  74. 2026-09-23 17:54 UTCEPSS rescore
  75. 2026-09-23 17:16 UTCGHSA enrichment

Publicly available exploits

(5 references)

Working exploit code is in the public domain (4 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCdahnutz/zimbra-cve-2026-73570-ir
    First seen Sep 4, 2026

    Detection-first, evidence-preserving incident-response toolkit for Zimbra CVE-2026-73570. Includes read-only host checks, IOC feeds, triage, persistence, containment, and recovery guidance based on sanitized incident evidence.

    Open source ↗
  • GitHub PoCgabrielunknown/CVE-2026-73570
    First seen Aug 26, 2026

    Zimbra SNMP Notification OS Command Injection — Unauthenticated RCE via SMTP exploit (Poc)

    Open source ↗
  • GitHub PoCjishino567/CVE-2026-73570
    First seen Aug 25, 2026

    PoC for CVE-2026-73570 (Zimbra SMTP Command Injection)

    Open source ↗
  • GitHub PoCHORKimhab/CVE-2026-73570
    First seen Aug 21, 2026

    CVE-2026-73570

    Open source ↗
  • Nucleinetwork/cves/2026/CVE-2026-73570.yaml
    First seen Jan 1, 2026

    Zimbra Collaboration Suite < 10.1.20 - OS Command Injection

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2026-73570?
CVE-2026-73570 is a critical vulnerability published on August 13, 2026. 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…
When was CVE-2026-73570 disclosed?
CVE-2026-73570 was first published on August 13, 2026, with the most recent update on August 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73570 actively exploited?
Yes. CISA added CVE-2026-73570 to the Known Exploited Vulnerabilities catalog on August 21, 2026, affecting Synacor Zimbra Collaboration Suite (ZCS). KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation, and watch the vendor's advisory for the fix.
What is the CVSS score of CVE-2026-73570?
CVE-2026-73570 has a CVSS base score of 8.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2026-73570?
CVE-2026-73570 affects Synacor Zimbra Collaboration Suite (ZCS).
How do I remediate CVE-2026-73570?
No fix for CVE-2026-73570 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-73570 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-73570

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