CVE-2026-100909: OctoberCMS · Server-Side Request Forgery
Affects OctoberCMSSource CVE Database V5
Public exploit available · CVSS 6.9 Medium : upgrade to 4.3.5 as a priority.
Data as of 10 Nov 2026, 23:24 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.3.5
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 28 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Upgrade octobercms/october to 4.3.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| OctoberCMS | Affected
| Fixed in– |
GitHuboctobercms/octoberpkg:github/octobercms/octoberOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:octobercms:octobercms:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade affected OctoberCMS installations to version 4.3.5 or 4.4.0 to apply the official patch and remediate the SSRF vulnerability. No other mitigation steps are indicated.
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.
References
- vuldb.com/vuln/410869 (opens in a new tab)
- vuldb.com/vuln/410869/cti (opens in a new tab)
- vuldb.com/cve/CVE-2026-100909 (opens in a new tab)
- vuldb.com/submit/919993 (opens in a new tab)
- github.com/octobercms/october/security/advisories/GHSA-2xmm-m4wv-3fjh (opens in a new tab)
- github.com/0xGenesi/CVE/blob/main/October_CMS_Stream_Wrapper_Injection.md (opens in a new tab)
- github.com/octobercms/october/commit/0e9736aa2c6d6bd3d60ff6ef9e0b4d32ce387f58 (opens in a new tab)
- github.com/octobercms/october/releases/tag/v4.3.5 (opens in a new tab)