CVE-2026-30940

baserCMS: Path Traversal in Theme File API Leads to Arbitrary File Write and RCE

HIGH
7.2
CVSS Score
Published: March 31, 2026 at 12:45 AM UTC
Updated: June 17, 2026 at 10:33 AM UTC
2 products affected across 2 vendorsBasercmsBasercms

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Severity
HIGH7.2
Exploit prediction
EPSS 1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.2.3
Affected range stops below 5.2.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/baserproject/basercms/security/advisories/GHSA-c5c6-37vq-pjcq
x_refsource_MISCVendor Advisory
Source: cverecord
https://basercms.net/security/JVN_20837860
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/baserproject/basercms/releases/tag/5.2.3

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-22CWE-73

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