Medium [CVE-2026-20308] Cisco IOS XE Software Web-Based Management Interface Denial of Service Vulnerability
This medium-severity Cisco advisory covers CVE-2026-20308 affecting Aironet Access Point Software (IOS XE Controller), IOS XE Catalyst SD-WAN, IOS XE Software Bootloader (ROMMON).
Android app · Google Play
Monitor future Cisco CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an authenticated, remote attacker with low privileges to perform a denial of service (DoS) attack against an affected device. The flaw is caused by insufficient input validation.
Affected products named by the advisory: Aironet Access Point Software (IOS XE Controller); IOS XE Catalyst SD-WAN; IOS XE Software Bootloader (ROMMON); IOS XG Software; and 1 more.
Affected products named by the advisory: IOS XR Software.
- Scope: At the time of publication, this vulnerability affected Cisco IOS XE Software if it had the web-based management interface enabled.
Official advisory · high-confidence parse· fetched 2 hours 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 hours ago·verify at source
Mitigation checklist
- There are no workarounds that address this vulnerability. However, there is a mitigation.
- Disabling the HTTP Server feature eliminates the attack vector for these vulnerabilities and may be a suitable mitigation until affected devices can be upgraded. To disable the HTTP Server feature, use the no ip http server or no ip http secure-server command in global configuration mode. If both the HTTP server and HTTPS server are in use, both commands are required to disable the HTTP Server …
- Allowing only trusted networks to access the HTTP server will limit exposure to these vulnerabilities. The following example shows how to allow remote access to the HTTP server from the trusted 192.168.10.0/24 network:
- !
- ip http access-class ipv4 restrict_ipv4_webui
- !
- ip access-list standard restrict_ipv4_webui
- permit 192.168.10.0 0.0.0.255
- !
- For additional information, see Filter Traffic Destined to Cisco IOS XE Devices WebUI Using an Access List.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.