CVE-2026-100909
High
Description
A vulnerability was found in OctoberCMS up to 4.1.19/4.2.25/4.3.4. The impacted element is the function getSourcePathForResize of the file modules/system/classes/ResizeImages.php. The manipulation of the argument realSourcePath results in server-side request forgery. The attack may be performed from remote. The exploit has been made public and could be used. Upgrading to version 4.3.5 and 4.4.0 is sufficient to resolve this issue. The patch is identified as 0e9736aa2c6d6bd3d60ff6ef9e0b4d32ce387f58. The affected component should be upgraded.
SeverityHigh
CVSS7.3
Exploit probability—
ProductOctober/october
PublishedSep 28, 2026
First seenSep 28, 2026
Weakness typeCWE-918Server-side request forgery (SSRF)
How to fix
Update
- october/october4.3.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| october/octoberPackagist | 4.3.0 ≤ v < 4.3.5 | 4.3.5 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.