What is CVE-2021-36091?

CVE-2021-36091 is a low-severity vulnerability in Otrs, classified under Information Disclosure. CVSS score: 3.5/10. Published 2021-07-26.

How severe is CVE-2021-36091?

Low severity. CVSS v3 base score is 3.5 out of 10.

Auth bypass in Otrs

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.

Vulnerability class: Information Disclosure

Published 2021-07-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: -0.000

Affected products

Otrs
Otrs Ag — versions 7.0.x
Otrs Ag ((Otrs)) Community Edition — versions 6.0.1

Weakness classification (CWE)

References

otrs.com/release-notes/otrs-security-advisory-2021-14/ (Vendor Advisory)
lists.debian.org/debian-lts-announce/2023/08/msg00040.html (mailing-list)

Frequently asked questions

What is CVE-2021-36091?: CVE-2021-36091 is a low-severity vulnerability in Otrs, classified under Information Disclosure. CVSS score: 3.5/10. Published 2021-07-26.
How severe is CVE-2021-36091?: Low severity. CVSS v3 base score is 3.5 out of 10.