CRITICAL · CVSS 9.8
ACTIVELY EXPLOITED
PATCH AVAILABLE
CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
| Vendor | Cisco |
|---|---|
| Product | Secure Email Gateway |
| CVSS score | 9.8 · CVSS 3.1 · CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 6.2% (percentile 94) |
| Actively exploited | Yes, according to CISA KEV |
| Added to CISA KEV | 14 Oct 2026 |
| CISA federal deadline | 17 Oct 2026 |
| Weakness (CWE) | CWE-23 |
| NVD published | 14 Oct 2026 |
| NVD last modified | 15 Oct 2026 |
| NVD status | Analyzed |
Affected versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Cisco Asyncos | from 15.0 before 15.5.5-014 | 15.5.5-014 |
| Cisco Asyncos | from 16.0 before 16.5.0-780 | 16.5.0-780 |
Required action (CISA's text)
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.
Description (NVD)
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.
Vendor advisories
SOURCES
Other Cisco flaws
- CVE-2026-20320: Cisco BroadWorks Improper Restriction of XML External Entity Reference Vulnerability
- CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
- CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
- CVE-2026-76461: Cisco Secure Email Gateway SQL Injection Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 15 Oct 2026.