Rising fast KEV catalog No authentication
CVE-2026-76519

Cisco Secure Email Gateway Relative Path Traversal Vulnerability

A vulnerability in the Advanced Malware Protection (AMP) feature of Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system. This vulnerability is due to…

CheckOps priority index
5.8/10 Patch within 7 days
Severity9.8
Probability0.2
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 2.2% higher than 82.1% of CVEs
CVSS 3.1 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 20 days 14 Oct 2026
CISA due date 17 Oct 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010015 Oct20 Oct24 Oct29 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)14 Oct 2026
  • Exploited in EUVD (ENISA)14 Oct 2026
  • Used by ransomwareno
  • EPSS above 10 %2.2%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

A vulnerability in the Advanced Malware Protection (AMP) feature of Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system. This vulnerability is due to improper handling of email attachments when the file reputation service is enabled. An attacker could exploit this vulnerability by sending an email that contains a crafted attachment through an affected device. A successful exploit could allow the attacker to write arbitrary files and execute commands with root privileges on the underlying operating system.

Affected products

Cisco Secure EmailSecure Email Gateway
Affected versions
  • 16.0.2-112
  • 15.5.0-048
  • 13.5.1-277
  • 14.2.0-620
  • 15.5.1-055
  • 15.5.4-012
  • 15.0.1-030
  • 13.0.0-392
  • 15.0.3-002
  • 14.2.1-020
  • 15.5.3-022
  • 16.0.0-050
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-76418Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
    5.3 · Rising fast
  • CVE-2026-76504Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
    7.5 · Actively exploited
  • CVE-2026-76460Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
    8.7 · Actively exploited
  • CVE-2026-76461Cisco Secure Email Gateway SQL Injection Vulnerability
    7.2 · Actively exploited
  • CVE-2026-20079Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
    9.1 · Actively exploited
  • CVE-2026-20349Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
    5.3 · Actively exploited

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities