CVE-2026-20108: A vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager could allow an authenti

Routine

MEDIUM 5.4UPGRADE

CVE-2026-20108 is a medium-severity flaw (CVSS 5.4) affecting catalyst sd-wan manager. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface of an affected device. This vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user of the web-based management interface to click a crafted link. A successful ex

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 94%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-03-25
Last modified	2026-06-29

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

Last updated 2026-06-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-25 16:16 UTCPublished CVE record published
2026-06-29 18:10 UTCUpdated Record last modified

cisco catalyst sd-wan manager UPGRADE

Affected: >= 20.12 and < 20.12.5.3 · >= 20.13 and < 20.15.4.2 · >= 20.16 and < 20.18.2.1 · 20.12.6

Fixed in: 20.12.5.3, 20.15.4.2, 20.18.2.1

Safe to downgrade to: a release before 20.12

1. Check installed version

apt-cache policy catalyst-sd-wan-manager || rpm -q catalyst-sd-wan-manager || catalyst-sd-wan-manager --version

2. UPGRADE to 20.12.5.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade catalyst-sd-wan-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade catalyst-sd-wan-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 20.12 (Debian / Ubuntu)

apt-cache madison catalyst-sd-wan-manager sudo apt install catalyst-sd-wan-manager=<VERSION_BEFORE_20.12> sudo apt-mark hold catalyst-sd-wan-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list catalyst-sd-wan-manager sudo dnf downgrade catalyst-sd-wan-manager-<VERSION_BEFORE_20.12> sudo dnf versionlock add catalyst-sd-wan-manager

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-20108?

catalyst sd-wan manager: upgrade to 20.12.5.3, 20.15.4.2, 20.18.2.1. Exact commands for each OS are on this page.

Is CVE-2026-20108 being exploited?

CVE-2026-20108 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-2026-20108 affect?

CVE-2026-20108 affects catalyst sd-wan manager. Severity is medium (CVSS 5.4). A vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface of an affected device. Th

How urgent is CVE-2026-20108?

Priority 20/100. No elevated risk signals yet.

Software pages

Cisco vulnerabilities

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References

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