Is CVE-2026-20278 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-20278 being exploited in the wild.

How severe is CVE-2026-20278?

High severity, with a CVSS score of 8.8, published 2 September 2026.

Is there a fix for CVE-2026-20278?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-20278 attacked?

It is attacked over the network, in an operating system.

Am I affected by CVE-2026-20278?

Check whether you run Cisco IOS XR at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-20278: Cisco IOS XR Software improper neutralization in command processing

CVE-2026-20278 · Severity: high · CVSS 8.8 · Published 2026-09-02

Cisco IOS XR Software contains multiple internally discovered vulnerabilities related to improper handling of user input and command processing. An attacker with network access could exploit these weaknesses to achieve remote code execution, bypass authentication, or cause denial of service on network devices running IOS XR. Cisco has released patched software versions to address these issues, which affect all IOS XR releases.

Technologies: Cisco IOS XR. Vendors: Cisco.

Quick answers

Is CVE-2026-20278 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-20278 being exploited in the wild.
How severe is CVE-2026-20278?: High severity, with a CVSS score of 8.8, published 2 September 2026.
Which products and versions are affected?: Cisco IOS XR all releases.
Is there a fix for CVE-2026-20278?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-20278 attacked?: It is attacked over the network, in an operating system.
Am I affected by CVE-2026-20278?: Check whether you run Cisco IOS XR at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

CVE-2026-20278 is one of seven vulnerabilities grouped under a comprehensive security hardening release for Cisco IOS XR Software. This specific CVE addresses improper neutralization issues (CWE-707), which include improper handling of special elements in commands and inadequate input validation. The vulnerabilities affect all releases of Cisco IOS XR Software, including IOS XR7 (LNT), with no authentication or special configuration required for exploitation. An unauthenticated remote attacker can exploit these network-accessible vulnerabilities to achieve high-impact outcomes including remote code execution, information disclosure, or system compromise. Cisco has released fixed software versions and approximately 16 Standalone Maintenance Updates (SMUs) per release to remediate these issues; no workarounds are available.

Affected products

Cisco IOS XR all releases

Timeline

2026-09-02: disclosed: Advisory published

References

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