High8.6Cisco

High [CVE-2026-20086] Cisco IOS XE Wireless Controller Software for the Catalyst CW9800 Family CAPWAP Denial of Service Vulnerability

This high-severity Cisco advisory covers CVE-2026-20086 affecting Cisco IOS XE Software 17.14.1, Cisco IOS XE Software 17.15.1, Cisco IOS XE Software 17.15.3.

cisco-sa-wlc-dos-hnX5KGOm Published Mar 25, 2026Updated by vendor Mar 25, 2026

CVE-2026-20086

Affected products & platforms

CiscoSwitchesWirelessCatalystIOS XE

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Summary

A vulnerability in the processing of Control and Provisioning of Wireless Access Points (CAPWAP) packets of Cisco IOS XE Wireless Controller Software for the Catalyst CW9800 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper handling of a malformed CAPWAP packet. An attacker could exploit this vulnerability by sending a malformed CAPWAP packet to an affected device.

A successful exploit could allow the attacker to cause the affected device to reload unexpectedly, resulting in a DoS …

Affected products named by the advisory: Cisco IOS XE Software 17.14.1; Cisco IOS XE Software 17.15.1; Cisco IOS XE Software 17.15.3; Cisco IOS XE Software 17.15.2b; and 2 more.

Affected versions

Scope: This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco IOS XE Wireless Controller Software, regardless of device configuration:

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Mitigation checklist

Workaround status

There are no workarounds that address this vulnerability.

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Cisco Security Advisories (PSIRT)official
Official vendor feed — the source of truth for this advisory. VulniPulse polled this feed and parsed this entry from it. Discovered from the machine-readable feed https://sec.cloudapps.cisco.com/security/center/psirtrss20/CiscoSecurityAdvisory.xml; this link opens the Cisco advisory index instead of the raw feed document.
Cisco
Vendor advisory pageofficial
Advisory page fetched and parsed to extract affected/fixed versions and mitigation guidance beyond what the feed carries.
Cisco

Cross-references

Validate CVE metadata against the authoritative registries.

CVE-2026-20086NVD CVE.org MITRE

Official resources

Cisco Catalyst 9800 Wireless Controller upgrade guide
Official documentation
Official upgrade documentation for Cisco Catalyst 9800 Wireless LAN Controllers.
Cisco Catalyst switch software upgrade guide
Official documentation
Official upgrade documentation for Cisco Catalyst campus switches (IOS XE).
Cisco Software Checker
Official documentation
Official tool to confirm whether your exact IOS / IOS XE / NX-OS / ASA / FTD / SD-WAN release is affected and to find the first fixed release.

Discussion(0)

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