Is CVE-2026-76442 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-76442 being exploited in the wild.

How severe is CVE-2026-76442?

High severity, with a CVSS score of 7.5, published 14 September 2026.

Which products and versions are affected?

Cisco Secure Email and Web Manager 15.5 and earlier; 16.0; 16.5 before 16.5.0-429; Cisco Secure Email Gateway 15.5 and earlier; 16.0; 16.5 before 16.5.0-780.

Is there a fix for CVE-2026-76442?

A patch was published on 2026-09-14: Fixed releases available: ESA 15.5.5-014 / 16.5.0-780, ESWM 15.5.5-006 / 16.5.0-429 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-76442 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-76442?

Check whether you run Cisco Secure Email and Web Manager or Cisco Secure Email Gateway at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-76442: Cisco Secure Email Gateway improper input validation

CVE-2026-76442 · Severity: high · CVSS 7.5 · Published 2026-09-14

Cisco Secure Email Gateway and Secure Email and Web Manager are email security appliances used to filter threats and manage message flow in enterprise environments. This vulnerability involves improper validation of quantity fields in input, which could allow attackers to trigger excessive resource consumption and degrade service availability.

Technologies: Cisco Secure Email and Web Manager, Cisco Secure Email Gateway. Vendors: Cisco.

Quick answers

Is CVE-2026-76442 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-76442 being exploited in the wild.
How severe is CVE-2026-76442?: High severity, with a CVSS score of 7.5, published 14 September 2026.
Which products and versions are affected?: Cisco Secure Email and Web Manager 15.5 and earlier; 16.0; 16.5 before 16.5.0-429; Cisco Secure Email Gateway 15.5 and earlier; 16.0; 16.5 before 16.5.0-780.
Is there a fix for CVE-2026-76442?: A patch was published on 2026-09-14: Fixed releases available: ESA 15.5.5-014 / 16.5.0-780, ESWM 15.5.5-006 / 16.5.0-429 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-76442 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-76442?: Check whether you run Cisco Secure Email and Web Manager or Cisco Secure Email Gateway at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability (CVE-2026-76442) is classified under CWE-1284 (improper validation of specified quantity in input) and involves unbounded numeric fields that drive excessive resource consumption. It affects Cisco Secure Email Gateway and Cisco Secure Email and Web Manager regardless of device configuration. The issue is remotely exploitable over the network with no authentication or user interaction required. Attackers can craft malicious input with excessive numeric quantities to exhaust system resources and cause denial of service. Cisco has released fixed software versions: ESA 15.5.5-014, 16.5.0-780 and ESWM 15.5.5-006, 16.5.0-429.

Affected products

Cisco Secure Email Gateway 15.5 and earlier; 16.0; 16.5 before 16.5.0-780
Cisco Secure Email and Web Manager 15.5 and earlier; 16.0; 16.5 before 16.5.0-429

Timeline

2026-09-14: disclosed: Cisco advisory published as part of security hardening release
2026-09-14: patched: Fixed releases available: ESA 15.5.5-014 / 16.5.0-780, ESWM 15.5.5-006 / 16.5.0-429

References

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