CVE-2020-26034
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality...
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
- Record
CVE-2020-26034- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:P/I:N/A:N - Updated
- 2026-11-02
CVE List No score
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
- Record
CVE-2020-26034- Updated
- 2026-11-02
EUVDEUVD-2020-18664 No score
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
- Record
EUVD-2020-18664- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r5vx-622x-4rx2 No score
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality...
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
- Record
GHSA-r5vx-622x-4rx2- Updated
- 2026-11-02
OSV
An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.
- Record
CVE-2020-26034- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-26034 is a medium vulnerability (CVSS 4.3) in Zammad, published December 28, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.73%, the 54th percentile. No source names a fixed version.