CVE-2026-20125 Denial of service in Cisco IOS XE Software
An authenticated remote attacker can cause a Cisco IOS XE device to reload unexpectedly by sending malformed HTTP requests, resulting in a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20125?
CVE-2026-20125 is a high-severity denial of service vulnerability in Cisco IOS XE Software, published on 25 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A vulnerability in the HTTP Server feature of Cisco IOS Software and Cisco IOS XE Software Release 3E could allow an authenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending malformed HTTP requests to an affected device. A successful exploit could allow the attacker to cause a watchdog timer to expire and the device to reload, resulting in a DoS condition. To exploit this vulnerability, the attacker must have a valid user account.
Weakness: CWE-228
Which versions are affected by CVE-2026-20125?
How do I fix CVE-2026-20125?
No fix has been published for CVE-2026-20125 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-20125 being exploited?
There is no known exploitation of CVE-2026-20125 in the wild and no public exploit code.
Sources
Also known as GHSA-qhwv-qr62-wrrh.