CVE-2026-30940Public exploitNetwork attack vector

Administrator code execution via unsanitized theme path

Published Mar 31, 2026 · Updated Mar 31, 2026

Path traversal in the baserCMS theme file API before 5.2.3 allows remote authenticated users to write arbitrary files. The BcThemeFileService::getFullpath method appends the unsanitized path parameter to the theme view path, so ../ segments escape the theme directory. Administrator access and an enabled core admin API permit a PHP file to be placed in the webroot and executed remotely; default API settings require an exploit chain.

CVSS severity7.2
High
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in the baserCMS theme file API before 5.2.3 allows remote authenticated users to write arbitrary files. The BcThemeFileService::getFullpath method appends the unsanitized path parameter to the theme view path, so ../ segments escape the theme directory. Administrator access and an enabled core admin API permit a PHP file to be placed in the webroot and executed remotely; default API settings require an exploit chain.

The record

CVE
CVE-2026-30940
Published
Mar 31, 2026
Updated
Mar 31, 2026
Vendor
baserCMS Users Community
Product
baserCMS
Classifications
CWE-73, CWE-22, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 5.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

baserCMS Users Community · baserCMSversion=< 5.2.3

Published CVSS scores

7.2GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-73External Control of File Name or Path
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1505.003Web Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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