# CVE-2026-76497: Cisco Expressway Series insecure temporary files

Source: https://junglewise.ai/threats/cve-2026-76497-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-76497 · Severity: medium · CVSS 6.6 · Published 2026-10-21

Cisco Expressway Series, which manages video communications and unified collaboration traffic in enterprise networks, contains insecure temporary file handling that could allow a network-based attacker to interfere with system operations or access sensitive data. An attacker can exploit this vulnerability without authentication or user interaction to cause service outages or read confidential information stored by the application.

Technologies: [Cisco Expressway-C](https://junglewise.ai/threats/technologies/expressway-c), [Cisco Expressway-E](https://junglewise.ai/threats/technologies/expressway-e). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2026-76497 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76497 being exploited in the wild.

**How severe is CVE-2026-76497?** Medium severity, with a CVSS score of 6.6, published 21 October 2026.

**Which products and versions are affected?** Cisco Expressway-C X14 and earlier, X15.5.3 and earlier; Cisco Expressway-E X14 and earlier, X15.5.3 and earlier.

**Is there a fix for CVE-2026-76497?** Yes: fixed in Expressway-C and Expressway-E: X15.5.20. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-76497 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-76497?** Check whether you run Cisco Expressway-C or Cisco Expressway-E 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.

## How to fix

- Fixed in Expressway-C and Expressway-E: X15.5.20

## Technical details

CVE-2026-76497 tracks insecure temporary file creation (CWE-377) in Cisco Expressway-C and Expressway-E devices. The vulnerability is exploitable over the network without authentication or user interaction. Successful exploitation enables denial of service or information disclosure through predictable temporary file paths.

## Affected products

- Cisco Expressway-C X14 and earlier, X15.5.3 and earlier
- Cisco Expressway-E X14 and earlier, X15.5.3 and earlier

## Timeline

- 2026-10-21: disclosed

## References

- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-exwy-hardening-FhcqBVcs](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-exwy-hardening-FhcqBVcs)

## Related threats

- [Cisco Expressway Series improper link resolution](https://junglewise.ai/threats/cve-2026-76496-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)
- [Cisco Expressway Series incorrect permission assignment](https://junglewise.ai/threats/cve-2026-76495-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)
- [Cisco Expressway Series code injection](https://junglewise.ai/threats/cve-2026-76494-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)
- [Cisco Expressway Series uncaught exceptions denial of service](https://junglewise.ai/threats/cve-2026-76493-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)
- [Cisco Expressway Series out-of-bounds write and code injection flaws](https://junglewise.ai/threats/cve-2026-76490-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)