CVE-2026-20178
CVE-2026-20178 is a medium-severity vulnerability in Cisco Webex Web App with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-601.
Key facts
- Severity: Medium (CVSS 3.x base score 4.3)
- EPSS exploit prediction: 0% (10th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-37759
- Weakness: CWE-601
- Affected product: Cisco Webex Web App
- Published:
- Last modified:
Description
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 vulnerability by persuading a user to click a crafted URL. A successful exploit could have allowed the attacker to redirect a user to a malicious website.
Frequently asked questions
- What is CVE-2026-20178?
- 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 vulnerability by persuading a user to click a crafted URL. A successful exploit could have allowed the attacker to redirect a user to a malicious website.
- How severe is CVE-2026-20178?
- CVE-2026-20178 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
- Is CVE-2026-20178 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-20178?
- CVE-2026-20178 affects Cisco Webex Web App. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-20178?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-20178 have an EU (EUVD) identifier?
- Yes. CVE-2026-20178 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37759.
- When was CVE-2026-20178 published?
- CVE-2026-20178 was published on 2026-06-17 and last updated on 2026-06-22.
References
Affected products (1)
- cpe:2.3:a:cisco:webex_web_app:-:*:*:*:*:-:*:*
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