CVE-2026-76519
Cisco Secure Email Gateway Relative Path Traversal Vulnerability
Cisco Secure Email GatewayNetwork & edge
CVSS
9.8CriticalExploit odds (EPSS)1.57%Chance of exploitation activity in the next 30 days, higher than 75% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
CISA required actionApply 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. CISA KEV
Patching is not enoughCISA requires federal agencies to look for signs of compromise on affected systems, not only patch (forensic triage under BOD 26-04). Treat exposed systems as possibly compromised. CISA guidance
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
Timeline
- 14 Oct 2026Added to CISA KEVCISA KEV
- 14 Oct 2026, 16:07 UTCPublishedCVE List
- 16 Oct 2026, 13:59 UTCFirst reported exploitedBluesky: zero-day
Vendor and government advisories 1
Vendors that say their products are affected, and agencies that issued alerts. Check each for the fixed release of the product you run.
Reports 4
3 outlets report exploitation. Reports are not confirmation; each links to its source.
- @guptadeepak.com: Cisco Secure Email Gateway CVE-2026-76519: root from a crafted attachment, exploited in the wild, now in CISA KEV. It is the second exploited Cisco email gateway flaw in about a moBluesky: exploited in the wild, 19 Oct 2026Exploitation reported
- @diesec.bsky.social: Cisco Secure Email Gateway Zero-Day Exploited Again Cisco Secure Email Gateway zero-day (CVE-2026-76519, CVSS 9.8): one crafted attachment gives unauthenticated root. In CISA KEV. Bluesky: zero-day, 19 Oct 2026Zero-day
- @netsecio.bsky.social: Cisco warns of a critical, actively exploited zero-day (CVE-2026-76519) in its Secure Email Gateway. The 9.8 CVSS flaw allows unauthenticated RCE with root access. Patch immediatelBluesky: zero-day, 16 Oct 2026Exploitation reportedZero-day
- Cisco Secure Email Gateway Arbitrary File Write VulnerabilityCisco PSIRT, 14 Oct 2026
Description
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.
Text from CVE List
Affected versions 23
- Cisco Secure Emailaffected: 14.0.0-698CVE List
- Cisco Secure Emailaffected: 13.5.1-277CVE List
- Cisco Secure Emailaffected: 13.0.0-392CVE List
- Cisco Secure Emailaffected: 14.2.0-620CVE List
- Cisco Secure Emailaffected: 13.0.5-007CVE List
- Cisco Secure Emailaffected: 13.5.4-038CVE List
- Cisco Secure Emailaffected: 14.2.1-020CVE List
- Cisco Secure Emailaffected: 14.3.0-032CVE List
- Cisco Secure Emailaffected: 15.0.0-104CVE List
- Cisco Secure Emailaffected: 15.0.1-030CVE List
- Cisco Secure Emailaffected: 15.5.0-048CVE List
- Cisco Secure Emailaffected: 15.5.1-055CVE List
- Cisco Secure Emailaffected: 15.5.2-018CVE List
- Cisco Secure Emailaffected: 16.0.0-050CVE List
- Cisco Secure Emailaffected: 15.0.3-002CVE List
- Cisco Secure Emailaffected: 16.0.0-054CVE List
- Cisco Secure Emailaffected: 15.5.3-022CVE List
- Cisco Secure Emailaffected: 16.0.1-017CVE List
- Cisco Secure Emailaffected: 15.5.4-012CVE List
- Cisco Secure Emailaffected: 16.0.4-016CVE List
- Cisco Secure Emailaffected: 15.0.5-016CVE List
- Cisco Secure Emailaffected: 16.0.2-112CVE List
- Cisco Secure Emailaffected: 16.0.3-044CVE List