CVE-2026-20277 Cisco IOS XR Software Security Hardening Release: September 2026
Cisco IOS XR contains protection mechanism failures allowing attackers to bypass security features, requiring a software update.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20277?
CVE-2026-20277 is a high-severity vulnerability in Cisco IOS XR Software, published on 2 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20277 are related to protection mechanism failure issues that are grouped under the Common Weakness Enumeration (CWE) CWE-693.
Weakness: CWE-693
Which versions are affected by CVE-2026-20277?
How do I fix CVE-2026-20277?
No fix has been published for CVE-2026-20277 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-20277 being exploited?
There is no known exploitation of CVE-2026-20277 in the wild and no public exploit code.
Sources
Also known as GHSA-6p8v-vwv7-4vg4.