How severe is CVE-2021-39136?

CVE-2021-39136 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-39136 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39136?

CVE-2021-39136 affects Basercms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39136?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-39136 published?

CVE-2021-39136 was published on 2021-08-25 and last updated on 2026-06-17.

CVE-2021-39136

CVE-2021-39136 is a high-severity vulnerability in Basercms with a CVSS 3.x base score of 8.7. 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: High (CVSS 3.x base score 8.7)
CVSS v2: 3.5
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Basercms
Published: 2021-08-25
Last modified: 2026-06-17

Description

baserCMS is an open source content management system with a focus on Japanese language support. In affected versions there is a cross-site scripting vulnerability in the file upload function of the management system of baserCMS. Users are advised to update as soon as possible. No workaround are available to mitigate this issue.

Frequently asked questions

What is CVE-2021-39136?: baserCMS is an open source content management system with a focus on Japanese language support. In affected versions there is a cross-site scripting vulnerability in the file upload function of the management system of baserCMS. Users are advised to update as soon as possible. No workaround are available to mitigate this issue.
How severe is CVE-2021-39136?: CVE-2021-39136 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-39136 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39136?: CVE-2021-39136 affects Basercms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39136?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-39136 published?: CVE-2021-39136 was published on 2021-08-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:basercms:basercms:*:*:*:*:*:*:*:*

More vulnerabilities in Basercms

CVE-2026-30880 — Critical (CVSS 9.8): baserCMS is a website development framework. Prior to version 5.2.3, baserCMS has an OS command injection vulnerability…
CVE-2026-27697 — Critical (CVSS 9.8): baserCMS is a website development framework. Prior to version 5.2.3, baserCMS has a SQL injection vulnerability in blog…
CVE-2023-43792 — Critical (CVSS 9.8): baserCMS is a website development framework. In versions 4.6.0 through 4.7.6, there is a Code Injection vulnerability…
CVE-2023-25655 — Critical (CVSS 9.8): baserCMS is a Content Management system. Prior to version 4.7.5, any file may be uploaded on the management system of…
CVE-2023-25654 — Critical (CVSS 9.8): baserCMS is a Content Management system. Prior to version 4.7.5, there is a Remote Code Execution (RCE) Vulnerability…
CVE-2017-10842 — Critical (CVSS 9.8): SQL injection vulnerability in the baserCMS 3.0.14 and earlier, 4.0.5 and earlier allows remote attackers to execute…

All CVEs affecting Basercms →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →