CVE-2026-20178: A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote

Routine

MEDIUM 4.3MITIGATE

CVE-2026-20178 is a medium-severity flaw (CVSS 4.3) affecting webex web app. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote attacker to redirect users to a malicious webpage. Cisco has addressed this vulnerability in the Cisco Webex App, and no customer action is needed. This vulnerability existed due to improper input validation of URL parameters in an HTTP request. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerab

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-601
Published	2026-06-17
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-17 18:17 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

cisco webex web app MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy webex-web-app || rpm -q webex-web-app || webex-web-app --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2026-20178?

webex web app: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-20178 being exploited?

CVE-2026-20178 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-2026-20178 affect?

CVE-2026-20178 affects webex web app. Severity is medium (CVSS 4.3). A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote attacker to redirect users to a malicious webpage. Cisco has addressed this vulnerability in the Cisco Webex App, and no customer

How urgent is CVE-2026-20178?

Priority 18/100. No elevated risk signals yet.

Software pages

Cisco vulnerabilities · Cisco Webex vulnerabilities

References

← Back to latest CVEs