How severe is CVE-2021-36551?

CVE-2021-36551 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-36551 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36551?

CVE-2021-36551 affects Tiki Tikiwiki Cms/groupware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36551?

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

When was CVE-2021-36551 published?

CVE-2021-36551 was published on 2021-10-28 and last updated on 2026-06-17.

CVE-2021-36551

CVE-2021-36551 is a medium-severity vulnerability in Tiki Tikiwiki Cms/groupware with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Tiki Tikiwiki Cms/groupware
Published: 2021-10-28
Last modified: 2026-06-17

Description

TikiWiki v21.4 was discovered to contain a cross-site scripting (XSS) vulnerability in the component tiki-calendar.php. This vulnerability allows attackers to execute arbitrary web scripts or HTML via a crafted payload under the Add Event module.

Frequently asked questions

What is CVE-2021-36551?: TikiWiki v21.4 was discovered to contain a cross-site scripting (XSS) vulnerability in the component tiki-calendar.php. This vulnerability allows attackers to execute arbitrary web scripts or HTML via a crafted payload under the Add Event module.
How severe is CVE-2021-36551?: CVE-2021-36551 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-36551 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36551?: CVE-2021-36551 affects Tiki Tikiwiki Cms/groupware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36551?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-36551 published?: CVE-2021-36551 was published on 2021-10-28 and last updated on 2026-06-17.

References

https://github.com/r0ck3t1973/xss_payload/issues/7

Affected products (1)

cpe:2.3:a:tiki:tikiwiki_cms\/groupware:21.4:*:*:*:*:*:*:*

More vulnerabilities in Tiki Tikiwiki Cms/groupware

CVE-2008-3653 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in TikiWiki CMS/Groupware before 2.0 have unknown impact and attack vectors.
CVE-2007-6529 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in TikiWiki before 1.9.9 have unknown impact and attack vectors involving (1)…
CVE-2025-34111 — Critical (CVSS 9.8): An unauthenticated arbitrary file upload vulnerability exists in Tiki Wiki CMS Groupware version 15.1 and earlier via…
CVE-2010-4239 — Critical (CVSS 9.8): Tiki Wiki CMS Groupware 5.2 has Local File Inclusion
CVE-2012-0911 — Critical (CVSS 9.8): TikiWiki CMS/Groupware before 6.7 LTS and before 8.4 allows remote attackers to execute arbitrary PHP code via a…
CVE-2020-29254 — High (CVSS 8.8): TikiWiki 21.2 allows templates to be edited without CSRF protection. This could allow an unauthenticated, remote…

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