CVE-2021-40128
Cisco Webex Meetings Email Content Injection Vulnerability
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an unauthenticated, remote attacker to send an account activation email with an activation link that points to an arbitrary domain. This vulnerability is due to insufficient validation of user-supplied parameters. An attacker could exploit this vulnerability by sending a crafted HTTP request to the account activation page of Cisco Webex Meetings. A successful exploit could allow the attacker to send to any recipient an account activation email that contains a tampered activation link, which could direct the user to an attacker-controlled website.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.3
Cisco Webex Meetings Email Content Injection Vulnerability
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an unauthenticated, remote attacker to send an account activation email with an activation link that points to an arbitrary domain. This vulnerability is due to insufficient validation of user-supplied parameters. An attacker could exploit this vulnerability by sending a crafted HTTP request to the account activation page of Cisco Webex Meetings. A successful exploit could allow the attacker to send to any recipient an account activation email that contains a tampered activation link, which could direct the user to an attacker-controlled website.
- Record
CVE-2021-40128- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-183
- Updated
- 2026-11-02
EUVDEUVD-2021-27315
5.3
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an unauthenticated, remote attacker to send an account activation email with an activation link that points to an arbitrary domain. This vulnerability is due to insufficient validation of user-supplied parameters. An attacker could exploit this vulnerability by sending a crafted HTTP request to the account activation page of Cisco Webex Meetings. A successful exploit could allow the attacker to send to any recipient an account activation email that contains a tampered activation link, which could direct the user to an attacker-controlled website.
- Record
EUVD-2021-27315- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f5wr-xjgr-jhq9
5.3
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an...
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an unauthenticated, remote attacker to send an account activation email with an activation link that points to an arbitrary domain. This vulnerability is due to insufficient validation of user-supplied parameters. An attacker could exploit this vulnerability by sending a crafted HTTP request to the account activation page of Cisco Webex Meetings. A successful exploit could allow the attacker to send to any recipient an account activation email that contains a tampered activation link, which could direct the user to an attacker-controlled website.
- Record
GHSA-f5wr-xjgr-jhq9- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
5.3
A vulnerability in the account activation feature of Cisco Webex Meetings could allow an unauthenticated, remote attacker to send an account activation email with an activation link that points to an arbitrary domain. This vulnerability is due to insufficient validation of user-supplied parameters. An attacker could exploit this vulnerability by sending a crafted HTTP request to the account activation page of Cisco Webex Meetings. A successful exploit could allow the attacker to send to any recipient an account activation email that contains a tampered activation link, which could direct the user to an attacker-controlled website.
- Record
CVE-2021-40128- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Weakness
- CWE-183
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-40128 is a medium vulnerability (CVSS 5.3) in Cisco Webex Meetings, published November 4, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.99%, the 62nd percentile. No source names a fixed version.