---
id: "CVE-2026-76492"
kind: "vulnerability"
aliases: ["CVE-2026-76492"]
title: "Cisco Expressway: null pointer flaws in hardening release"
severity: "high"
cvss: 7.5
epss: 0.00263
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Cisco Expressway Series (Expressway-C and Expressway-E)", "fixed": ["X15.5.20"], "affected": "X15.5.3 and earlier; X14 and earlier", "ecosystem": "vendor"}]
ecosystems: []
tags: ["cisco", "expressway", "expressway-c", "expressway-e", "infrastructure", "self-hosted"]
not_affected_if: ["none-known"]
published_at: "2026-10-21T17:19:08+00:00"
first_seen_at: "2026-10-23T21:57:29+00:00"
updated_at: "2026-10-25T03:42:12+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-76492", "first_seen_at": "2026-10-23T21:57:29+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-76492", "first_seen_at": "2026-10-24T13:15:54+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-25T03:20:34+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-25T03:42:12+00:00"}]
---

# Cisco Expressway: null pointer flaws in hardening release

Cisco Expressway Series hardening release fixes multiple null pointer dereferences (CWE-476) found in internal testing. Network-reachable, no authentication or user interaction, impact is availability (DoS). Cisco says not known to be exploited; no workarounds.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Cisco Expressway Series (Expressway-C and Expressway-E) affected X15.5.3 and earlier; X14 and earlier fixed X15.5.20

## How to check

Check the installed Expressway software version in the web UI or CLI. Vulnerable: X15.5.3 and earlier, X14 and earlier. Fixed: X15.5.20 or later. Affects Expressway-C and -E, virtual and appliance, any configuration.

## Fix

Upgrade Expressway-C/-E on X15.5.3 or earlier to X15.5.20. X14 and earlier: Cisco says 'migrate to a fixed release' (no version named); X15.5.20 is the first fixed release listed. No workarounds.

## Timeline

- 2026-10-23T21:57:29+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-76492
- 2026-10-24T13:15:54+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-76492
- 2026-10-25T03:20:34+00:00 analyst — Correction: removed unsourced CLI command from how_to_check; set who_affected from advisory text.
- 2026-10-25T03:42:12+00:00 analyst — Read Cisco advisory cisco-sa-exwy-hardening: X15.5.3 and earlier fixed in X15.5.20; X14 and earlier told to migrate to a fixed release (no specific version). No workarounds, no known exploitation. Advisory CVSS 8.6 is the max for the CWE-476 group (NVD 7.5); sibling CVEs 76490-76497 share the advisory.

## Documents

- [advisory] Cisco Expressway Series Security Hardening Release: October 2026 https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-exwy-hardening-FhcqBVcs

## From the sources

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Expressway Series software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.  

The vulnerabilities tracked by CVE-2026-76492 are related to issues concerning null pointers that are grouped under the Common Weakness Enumeration (CWE) Base CWE-476.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_