SSRF in Octobercms
CVE-2026-100909
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Octobercms — versions 4.1.0, 4.1.1, 4.1.10
Weakness classification (CWE)
References
- vuldb.com/vuln/410869 (technical-description, vdb-entry)
- vuldb.com/vuln/410869/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-100909 (third-party-advisory)
- vuldb.com/submit/919993 (third-party-advisory)
- github.com/octobercms/october/security/advisories/GHSA-2xmm-m4wv-3fjh (related)
- github.com/0xGenesi/CVE/blob/main/October_CMS_Stream_Wrapper_Injection.md (exploit)
- github.com/octobercms/october/commit/0e9736aa2c6d6bd3d60ff6ef9e0b4d32ce387f58 (patch)
- github.com/octobercms/october/releases/tag/v4.3.5 (patch)
Frequently asked questions
- What is CVE-2026-100909?
- CVE-2026-100909 is a high-severity vulnerability in Octobercms, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.3/10. Published 2026-09-28.
- How severe is CVE-2026-100909?
- High severity. CVSS v3 base score is 7.3 out of 10.