CVE-2026-76519
CriticalExploitedPublic exploitCisco Secure Email Gateway Arbitrary File Write Vulnerability
Published Oct 14, 2026 · Updated Oct 15, 2026 · Also known as EUVD-2026-101420, GHSA-6rc3-jwq8-jm3v
Key Facts
Patch immediately- CVE-2026-76519 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Asyncos (Cisco), Cisco Secure Email.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 14, 2026. Public exploit code is available.
- EPSS estimates a 1.6% probability of exploitation in the next 30 days.
- Fixed versions are available, including Asyncos 15.5.5-014, Asyncos 16.5.0-780.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
1.6%
Higher than 75.0% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-76519 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Oct 14, 2026 | Oct 17, 2026 | Not reported |
| Industry KEV feed | Oct 14, 2026 | Oct 17, 2026 | Not reported |
| CIRCL KEV | Oct 14, 2026 | Oct 17, 2026 | Not reported |
| ENISA EUVD | Oct 14, 2026 | n/a | Not reported |
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.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| AsyncosCisco | See advisory | 15.5.5-014 |
| Cisco Secure Email | >= 14.0.0-698 | n/a |
Patched Releases
Asyncos
15.5.5-014, 16.5.0-780
Timeline
Publicly disclosed
Oct 14, 2026
Added to CISA KEV
Oct 14, 2026
Added to Industry KEV feed
Oct 14, 2026
Added to CIRCL KEV
Oct 14, 2026
Added to ENISA EUVD
Oct 14, 2026
Last updated
Oct 15, 2026
Weakness Type
- CWE-23 Relative Path Traversal
References
FAQ
Common Questions.
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.
Affected: Asyncos (Cisco); Cisco Secure Email versions >= 14.0.0-698. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 14, 2026.
Yes. It was added on Oct 14, 2026 with a federal remediation due date of Oct 17, 2026.
Public exploit code is available.
Fixed versions are available, including Asyncos 15.5.5-014, Asyncos 16.5.0-780.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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