Cisco searched for IOS XR bugs and found so many it rolled them into an update release
Cisco patched three critical flaws, including CVE-2026-20212 unauthenticated remote root code execution in Nexus 9000 switches; no exploitation observed yet.
Cisco disclosed three critical-rated flaws found during a comprehensive internal security review. CVE-2026-20274 and CVE-2026-20279, both CVSS 9.8, affect the IOS XR carrier-grade operating system and are fixed in newly released versions. CVE-2026-20212 lets unauthenticated remote attackers execute code with root privileges on some Nexus 9000 Series Switches by reaching TCP ports 43210 and 43211 in the default Layer 3 VRF; no software fix exists yet, only infrastructure ACL mitigations. Cisco says it has not observed attacks against these flaws.
- CVE-2026-20212 allows unauthenticated root RCE on ten Nexus 9000 models
- IOS XR flaws CVE-2026-20274 and CVE-2026-20279 both rated CVSS 9.8
- Nexus flaw mitigated via iACLs; no permanent software fix yet
- Flaws found via internal review; no exploitation observed
- Vendors
- Cisco
- Products
- IOS XRNexus 9000Silicon One
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2026-20212 | Unauthenticated RCE in Cisco Nexus 9000 Switches with Silicon One Integration | 9.8 | <1% | ||
CVE-2026-20274+1 related CVE | Critical Improper Resource Control Flaws in Cisco IOS XR Software | 9.8 | <1% |
From the original article
2 min read at theregister.comThree critical vulns demand your attention, one a make-me-root mess in Nexus 9000 Series Switches that you can mitigate, not fix
By Simon Sharwood · theregister.com
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.