How severe is CVE-2021-42137?

CVE-2021-42137 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-42137 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42137?

CVE-2021-42137 affects Zammad. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42137?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-42137 published?

CVE-2021-42137 was published on 2021-10-11 and last updated on 2026-06-17.

CVE-2021-42137

CVE-2021-42137 is a medium-severity vulnerability in Zammad with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Zammad
Published: 2021-10-11
Last modified: 2026-06-17

Description

An issue was discovered in Zammad before 5.0.1. In some cases, there is improper enforcement of the privilege requirement for viewing a list of tickets that shows title, state, etc.

Frequently asked questions

What is CVE-2021-42137?: An issue was discovered in Zammad before 5.0.1. In some cases, there is improper enforcement of the privilege requirement for viewing a list of tickets that shows title, state, etc.
How severe is CVE-2021-42137?: CVE-2021-42137 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-42137 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42137?: CVE-2021-42137 affects Zammad. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42137?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42137 published?: CVE-2021-42137 was published on 2021-10-11 and last updated on 2026-06-17.

References

https://zammad.com/en/advisories/zaa-2021-19

Affected products (1)

cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:*

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