SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-16941

October CMS through 1.0.428 does not prevent use of .htaccess in themes, which allows remote authenticated users to execute arbitrary PHP code by downloading a theme ZIP archive from /backend/cms/themes, and then uploading and importing a modified…

HIGH 8.8EPSS 1.56%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

October CMS through 1.0.428 does not prevent use of .htaccess in themes, which allows remote authenticated users to execute arbitrary PHP code by downloading a theme ZIP archive from /backend/cms/themes, and then uploading and importing a modified archive with two new files: a .php file and a .htaccess file. NOTE: the vendor says "I don't think [an attacker able to login to the system under an account that has access to manage/upload themes] is a threat model that we need to be considering.

CVSS 3.0
8.8 HIGHCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
1.56% probability · 75th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-434
Affected
octobercms/october
Source
cve@mitre.org
EPSS trend
0%3%5%27 October 2026: 1.56%27 October 202627 October 2026

EPSS 1.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.