Medium severity · published Apr 21, 2026
CVE-2026-26067
October: Safe Mode Bypass via CSS Preprocessor Compilers
4.9
CVSS
0.2%
EPSS
No
On KEV
Description
October is a Content Management System (CMS) and web platform. Prior to 3.7.14 and 4.1.10, a server-side information disclosure vulnerability was identified in the handling of CSS preprocessor files. Backend users with Editor permissions could craft .less, .sass, or .scss files that leverage the compiler's import functionality to read arbitrary files from the server. This worked even with cms.safe_mode enabled. This vulnerability is fixed in 3.7.14 and 4.1.10.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OC
october · octobercms
>= 4.0.0, < 4.1.10; < 3.7.14 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-26067
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-26067
github.com
https://github.com/octobercms/october/security/advisories/GHSA-3888-q23f-x7qh
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October CMS build 412 is vulnerable to PHP code execution in the asset manager functionality resulting in site compromise and possibly other applications on the server
9.8
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October CMS build 412 is vulnerable to Apache configuration modification via file upload functionality resulting in site compromise and possibly other applications on the server