CVE-2026-76519
KEV: known exploited SSVC: activeCisco Secure Email Gateway Arbitrary File Write Vulnerability
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack conditions and impact
Derived from the CNA (via NVD) CVSS 3.1 vectorThis vulnerability may be exploitable over the internet without authentication or user interaction.
| Metric | Value | Meaning |
|---|---|---|
| Attack vector AV | N | Network |
| Attack complexity AC | L | Low (easy) |
| Privileges required PR | N | None |
| User interaction UI | N | None |
| Scope S | U | Unchanged |
| Confidentiality C | H | High |
| Integrity I | H | High |
| Availability A | H | High |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
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.
CISA KEV entry
Cisco Secure Email Gateway Relative Path Traversal Vulnerability — Cisco / Secure Email Gateway
Cisco Secure Email Gateway contains a relative path traversal vulnerability that could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system.
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.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-afw-zqYJkjxp ; ; 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-2026-76519
CVSS assessments
| Provider | Version | Score | Vector |
|---|---|---|---|
| NVD / [email protected] (Secondary) | 3.1 | 9.8 CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA / cisco | 3.1 | 9.8 CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products and packages
CNA (CVE.org)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Email | affected: 14.0.0-698 affected: 13.5.1-277 affected: 13.0.0-392 affected: 14.2.0-620 affected: 13.0.5-007 affected: 13.5.4-038 affected: 14.2.1-020 affected: 14.3.0-032 affected: 15.0.0-104 affected: 15.0.1-030 affected: 15.5.0-048 affected: 15.5.1-055 affected: 15.5.2-018 affected: 16.0.0-050 affected: 15.0.3-002 affected: 16.0.0-054 affected: 15.5.3-022 affected: 16.0.1-017 affected: 15.5.4-012 affected: 16.0.4-016 affected: 15.0.5-016 affected: 16.0.2-112 affected: 16.0.3-044 default: unknown |
NVD CPE (2)
Show CPE list
| Vendor | Product | Range | CPE |
|---|---|---|---|
| cisco | asyncos | >= 15.0, < 15.5.5-014 | cpe:2.3:o:cisco:asyncos:*:*:*:*:*:*:*:* |
| cisco | asyncos | >= 16.0, < 16.5.0-780 | cpe:2.3:o:cisco:asyncos:*:*:*:*:*:*:*:* |
Linux distribution status
References (2)
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-afw-zqYJkjxp NVD, CNA Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-76519 NVD, ADP CISA-ADP US Government Resourcegovernment-resource