Webex TeamsApplication · Cisco
CVE-2020-26067
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 the web-based interface of Cisco Webex Teams could allow an authenticated, remote attacker to conduct cross-site scripting attacks. The vulnerability is due to improper validation of usernames. An attacker could exploit this vulnerability by creating an account that contains malicious HTML or script content and joining a space using the malicious account name. A successful exploit could allow the attacker to conduct cross-site scripting attacks and potentially gain access to sensitive browser-based information.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
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 confidenceThis is a stored cross-site scripting (XSS) vulnerability in Cisco Webex Teams' web-based interface. The vulnerability stems from improper validation of usernames, allowing an authenticated attacker to inject malicious HTML or script content into their account name. When the attacker joins a space using this malicious username, the payload executes in victims' browsers, potentially exposing sensitive browser-based information.
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
Webex TeamsApplication
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
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/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 Cisco Webex Teams deploymentReview installed software or check the application version by launching the desktop client and navigating to Help > About Cisco Webex Teams, or check for the web application at webex.comAffected if Cisco Webex Teams (desktop or web) is in use in the environment
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Verify web interface is accessibleAttempt to access the Cisco Webex Teams web portal at teams.webex.com and confirm user authentication is possibleAffected if Users have access to the web-based interface for Cisco Webex Teams
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Review user account names for suspicious contentAs an administrator, use the Webex Control Hub or API to list all user accounts and inspect the displayName or username fields for HTML tags (<script>, <img>, javascript:, onerror=, etc.)Affected if Any user account contains HTML or script content in the username/display name fields
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Inspect recent space membership changesCheck Webex Control Hub audit logs or meeting/space activity logs for recent users who joined spaces, noting any users with unusual or encoded characters in their display namesAffected if Recent space join events involve users with potentially malicious usernames
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Check browser security logsIf accessible, review browser security logs or network traffic captures for XSS mitigation alerts triggered by Webex Teams web interface activityAffected if Browser XSS filters or CSP blocks are triggered when viewing Webex Teams spaces in the web interface
An environment is affected if Cisco Webex Teams (desktop or web) is deployed and users can access the web interface, as the vulnerability requires authenticated users to modify their usernames with malicious payloads that execute when joining spaces.
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 dataApply the Cisco software updates that address this vulnerability. No workarounds are available.
Fix this in Webex Teams
Scoped from the published advisory
- Consultation3.0 h
- Implementation2.0 h
- Testing2.0 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 $2,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-26067 — 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-2020-26067 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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- 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
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