CVE-2020-26034

Name: CVE-2020-26034
Creator: NVD / NIST
Published: 2020-12-28T08:15:11.427+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.72%

Last modified Jun 17, 2026

CVE-2020-26034 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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. EPSS estimates a 0.72% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.72%

49.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Zammad	Zammad	>= 1.0.0, < 3.4.1

References

https://zammad.com/news/security-advisory-zaa-2020-14Vendor Advisory
https://zammad.com/news/security-advisory-zaa-2020-14Vendor Advisory

Timeline

Published: Dec 28, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26034?

How severe is CVE-2020-26034?

CVE-2020-26034 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26034?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26034?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST