CyberSecBulletin
CVE-2026-20278NVD status: Awaiting Analysis

Cisco IOS XR Software: Improper Neutralization

Published Updated By the CyberSecBulletin desk

CVE-2026-20278 is a high-severity improper neutralization vulnerability in Cisco IOS XR Software from Cisco, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Cisco IOS XR Software versions: 6.5.29; 7.0.1; 6.5.26, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Cisco IOS XR Software you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco IOS XR Software6.5.29; 7.0.1; 6.5.26; 6.5.25; 6.5.28; 6.5.90; 7.1.1; 7.0.90; and 32 more rangesNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).

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-2026-20278 are related to improper neutralization issues that are grouped under the Common Weakness Enumeration (CWE) CWE-707.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization

The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being used when received from an upstream component, or before being sent to a downstream component.

More Improper Neutralization vulnerabilities (CWE-707)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco IOS XR Software

All Cisco IOS XR Software vulnerabilities

Recent Improper Neutralization vulnerabilities

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