WebexApplication · Cisco
CVE-2026-20149
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability in Cisco Webex could have allowed an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack. Cisco has addressed this vulnerability, and no customer action is needed. This vulnerability was due to improper filtering of user-supplied input. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by persuading a user to follow a malicious link. A successful exploit could have allowed the attacker to conduct an XSS attack against the targeted user.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA reflected cross-site scripting (XSS) vulnerability existed in Cisco Webex due to improper filtering of user-supplied input. An unauthenticated remote attacker could have exploited this by tricking users into following malicious links, allowing arbitrary script execution in the victim's browser. Cisco has since addressed this vulnerability.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
WebexApplication
all versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm you use Cisco WebexIdentify if your organization uses Webex for meetings, messaging, or video conferencing. Check for Webex desktop client installations, Webex web portal access, or Webex mobile apps in use.Affected if You use any Cisco Webex service (cloud-based meetings, messaging, or related web interfaces)
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Determine if this is the cloud or self-hosted deploymentClarify whether your Webex deployment is Cisco's cloud service or an on-premises/self-hosted Webex Meeting Server. This vulnerability may have been addressed differently depending on deployment type.Affected if You are using a self-hosted Webex Meeting Server deployment that may not have received automatic patches
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Check for vendor confirmation of patch applicationReview Cisco security advisories or release notes for CVE-2026-20149 to confirm the patch has been applied to your Webex service. For cloud users, verify Cisco has deployed the fix.Affected if You cannot confirm through Cisco documentation that the patch has been applied to your specific Webex environment
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Assess user awareness of phishing risksSince this is a reflected XSS requiring users to click malicious links, verify whether users have been trained to recognize and avoid clicking untrusted links, especially those appearing to come from Webex invitations or messages.Affected if Users are not trained to identify malicious links and could be tricked into clicking attacker-controlled URLs
You are affected if you use Cisco Webex and cannot confirm through Cisco's documentation that the XSS patch has been applied to your environment, particularly for self-hosted deployments.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataNo customer action is required as Cisco has already patched this vulnerability; however, users should remain vigilant about clicking untrusted links as a general security practice.
Fix this in Webex
Scoped from the published advisory
- Consultation1.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20149 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20149 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data