CVE-2021-40128

mediumpriority · track · 21EPSS 0.010 · 62 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.99% (62nd) EPSS
CVSS 5 · medium
Is it mine?
4 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

5.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · FSTEC (BDU) RU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · ENISA EU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · psirt@cisco.com USexploitability 3.9 · impact 1.4
v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · Cisco PSIRT US
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-183USCWE-183USCWE-20US
05

affected products (4)

Products and version ranges known to be affected.

06

advisories (1)

Vendor and ecosystem advisories describing this.

  • cisco-sa-webex-activation-3sdNFxcyCisco Webex Meetings Email Content Injection Vulnerability2021-11-03csaf · cisco_csafUS

    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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-activation-3sdNFxcy ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-activation-3sdNFxcy"]

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisco_csafnvdNVDCVE.orgMITRE
published 2021-11-04modified 2026-06-17
09

references (5)

External citations — patches, advisories, analysis.

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