---
title: "CVE-2026-101005: October CMS - Server-Side Request Forgery"
description: "October CMS <= 4.3.4 contains a server-side request forgery caused by improper validation in validateExternalImageHost function in System/Classes/ResizeImages.php, letting remote attackers forge server requests, exploit requires crafted request."
url: https://panop.io/threat-heartbeat/CVE-2026-101005/
---

# CVE-2026-101005 October CMS - Server-Side Request Forgery

October CMS <= 4.3.4 contains a server-side request forgery caused by improper validation in validateExternalImageHost function in System/Classes/ResizeImages.php, letting remote attackers forge server requests, exploit requires crafted request.

CVSS base score 7.3 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.30% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-101005)

## Details

Type

Server-Side Request Forgery

Impact

Server Side Request Forgery

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Published

28 September 2026

Updated

15 October 2026

Weakness

[CWE-918](https://cwe.mitre.org/data/definitions/918.html)

## Vendor fix

Upgrade to version 4.3.5.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-101005](https://nvd.nist.gov/vuln/detail/CVE-2026-101005)
- [https://vuldb.com/vuln/410875](https://vuldb.com/vuln/410875)
- [https://vuldb.com/vuln/410875/cti](https://vuldb.com/vuln/410875/cti)
- [https://www.cybersecurity-help.cz/vdb/vulns/149488/](https://www.cybersecurity-help.cz/vdb/vulns/149488/)
- [https://github.com/0xGenesi/CVE/blob/main/October\_CMS\_SSRF\_IPv6\_Mapped\_IPv4\_Bypass.md](https://github.com/0xGenesi/CVE/blob/main/October_CMS_SSRF_IPv6_Mapped_IPv4_Bypass.md)
- [https://github.com/octobercms/october/releases/tag/v4.3.5](https://github.com/octobercms/october/releases/tag/v4.3.5)
- [https://github.com/octobercms/october/security/advisories/GHSA-j2j7-7m99-6226](https://github.com/octobercms/october/security/advisories/GHSA-j2j7-7m99-6226)
- [https://vuldb.com/cve/CVE-2026-101005](https://vuldb.com/cve/CVE-2026-101005)
- [https://vuldb.com/submit/922294](https://vuldb.com/submit/922294)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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