Zoom Workplace: Improper Authorization in Handler for Custom URL Scheme
CVE-2026-53407 is a critical-severity improper authorization in handler for custom URL scheme vulnerability in Zoom Workplace from Zoom Communications, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 7.0.4 as the first without the flaw, so updating Zoom Workplace to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Zoom Workplace to 7.0.4 or a later version.
- Update Workplace to 7.0.3 or 7.0.4, whichever matches your release line, or a later version.
- Read the advisory on zoom.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zoom Communications | Zoom Workplace | before 7.0.4 | 7.0.4 |
| Zoom | Workplace | before 7.0.3; before 7.0.4 | 7.0.3, 7.0.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | CNA (zoom.us) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Improper Authorization in Handler for Custom URL Scheme in Zoom Workplace before version 7.0.4 for Android and before 7.0.3 for iOS may allow an unauthenticated user to conduct an escalation of privilege via network access.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authorization in Handler for Custom URL Scheme
The product uses a handler for a custom URL scheme, but it does not properly restrict which actors can invoke the handler using the scheme.
How developers prevent this class of flaw
- Utilize a user prompt pop-up to authorize potentially harmful actions such as those modifying data or dealing with sensitive information. When designing functionality of actions in the URL scheme, consider whether the action should be accessible to all mobile applications, or if an allowlist of applications to interface with is appropriate.
More Improper Authorization in Handler for Custom URL Scheme vulnerabilities (CWE-939)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Zoom Workplace
- 8.0 High severity
- 8.1 High severity
- 8.1 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Authorization in Handler for Custom URL Scheme vulnerabilities
- 8.7 High severity
- 8.8 High severity
- 8.0 High severity
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