How severe is CVE-2021-36091?

CVE-2021-36091 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-36091 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36091?

CVE-2021-36091 primarily affects Otrs. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36091?

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

When was CVE-2021-36091 published?

CVE-2021-36091 was published on 2021-07-26 and last updated on 2026-06-17.

CVE-2021-36091

CVE-2021-36091 is a low-severity vulnerability in Otrs with a CVSS 3.x base score of 3.5. 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: Low (CVSS 3.x base score 3.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Otrs
Published: 2021-07-26
Last modified: 2026-06-17

Description

Agents are able to list appointments in the calendars without required permissions. This issue affects: OTRS AG ((OTRS)) Community Edition: 6.0.x version 6.0.1 and later versions. OTRS AG OTRS: 7.0.x versions prior to 7.0.27.

Frequently asked questions

What is CVE-2021-36091?: Agents are able to list appointments in the calendars without required permissions. This issue affects: OTRS AG ((OTRS)) Community Edition: 6.0.x version 6.0.1 and later versions. OTRS AG OTRS: 7.0.x versions prior to 7.0.27.
How severe is CVE-2021-36091?: CVE-2021-36091 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-36091 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36091?: CVE-2021-36091 primarily affects Otrs. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36091?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-36091 published?: CVE-2021-36091 was published on 2021-07-26 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:otrs:otrs:*:*:*:*:community:*:*:*
cpe:2.3:a:otrs:otrs:*:*:*:*:*:*:*:*

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