CVE-2026-20272: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software eng

This month

CRITICAL 9.8REMOTEMITIGATE

CVE-2026-20272 is a critical-severity flaw (CVSS 9.8) affecting ios xe. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20272 are related to issues with improper neutralization of special elements that are grouped under the Common Wea

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-74
Published	2026-08-05
Last modified	2026-10-23

Publisher (CNA): Cisco Systems, Inc. · Vendor: cisco

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-05 17:16 UTCPublished CVE record published
2026-10-23 21:10 UTCUpdated Record last modified

cisco ios xe MITIGATE

Affected: 16.6.2 · 16.6.3 · 16.6.4 · 16.6.4a · 16.6.4s · 16.6.5 · 16.6.5a · 16.6.5b

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.6.2

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · python-openslide · FIXED · 1.4.7-1.fc46 · FEDORA-2026-336bea884e · source

sudo dnf upgrade --advisory=FEDORA-2026-336bea884e

Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source

sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-20272?

ios xe: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-20272 being exploited?

CVE-2026-20272 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-20272 affect?

CVE-2026-20272 affects ios xe. Severity is critical (CVSS 9.8). As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that add

How urgent is CVE-2026-20272?

Priority 54/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

iOS vulnerabilities · Cisco IOS XE vulnerabilities · Cisco vulnerabilities

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CVE-2026-20271 HIGH 8.6 MITIGATE As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software eng

References

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