How severe is CVE-2026-30940?

CVE-2026-30940 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-30940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-30940?

CVE-2026-30940 affects Basercms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-30940?

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.

Does CVE-2026-30940 have an EU (EUVD) identifier?

Yes. CVE-2026-30940 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17267.

When was CVE-2026-30940 published?

CVE-2026-30940 was published on 2026-03-31 and last updated on 2026-06-17.

CVE-2026-30940

CVE-2026-30940 is a high-severity vulnerability in Basercms with a CVSS 3.x base score of 7.2. 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-22.

Key facts

Severity: High (CVSS 3.x base score 7.2)
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17267
Weakness: CWE-22
Affected product: Basercms
Published: 2026-03-31
Last modified: 2026-06-17

Description

baserCMS is a website development framework. Prior to version 5.2.3, a path traversal vulnerability exists in the theme file management API (/baser/api/admin/bc-theme-file/theme_files/add.json) that allows arbitrary file write. An authenticated administrator can include ../ sequences in the path parameter to create a PHP file in an arbitrary directory outside the theme directory, which may result in remote code execution (RCE). This issue has been patched in version 5.2.3.

Frequently asked questions

What is CVE-2026-30940?: baserCMS is a website development framework. Prior to version 5.2.3, a path traversal vulnerability exists in the theme file management API (/baser/api/admin/bc-theme-file/theme_files/add.json) that allows arbitrary file write. An authenticated administrator can include ../ sequences in the path parameter to create a PHP file in an arbitrary directory outside the theme directory, which may result in remote code execution (RCE). This issue has been patched in version 5.2.3.
How severe is CVE-2026-30940?: CVE-2026-30940 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-30940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-30940?: CVE-2026-30940 affects Basercms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-30940?: 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.
Does CVE-2026-30940 have an EU (EUVD) identifier?: Yes. CVE-2026-30940 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17267.
When was CVE-2026-30940 published?: CVE-2026-30940 was published on 2026-03-31 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-22 (Path Traversal) vulnerabilities

CVE-2026-48282 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Limitation of a Pathname to a Restricted…
CVE-2026-54917 — Critical (CVSS 10.0): SeaweedFS is a distributed storage system for object storage (S3), file systems, and Iceberg tables. Prior to 4.30, the…
CVE-2026-11429 — Critical (CVSS 10.0): Two endpoints in the Vault Service ScriptsController, shared by Altium Enterprise Server and Altium 365, accept file…
CVE-2026-34909 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices to…
CVE-2026-7411 — Critical (CVSS 10.0): In Eclipse BaSyx Java Server SDK versions prior to 2.0.0-milestone-10, inadequate path normalization in the Submodel…
CVE-2026-36767 — Critical (CVSS 10.0): A path traversal vulnerability in the /content/images/add endpoint of shopizer v3.2.5 allows attackers write arbitrary…

Browse all CWE-22 (Path Traversal) vulnerabilities →