vulnerability / NVI-00007859 / Revision 3
October CMS: Incomplete Scheme Validation in Image Resizer
OSV carries this publisher advisory for october/october. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
0.298%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.22584. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
october/october
source listedECOSYSTEM: introduced 4.3.0; fixed 4.3.5
The image resizer classified external sources by testing whether the source string began with the substring `http`, and the string-source branch in `ResizeImageItem::fromObject()` accepted any value containing `://` as a URL. As a result, non-http(s) PHP stream wrappers such as `phar://`, `file://` and `ftp://` could be stored in the resizer cache and later passed to the underlying image library. On a `phar://` path this can lead to metadata deserialization during subsequent file operations. **Exploitation requires an existing template-authoring or backend-configuration primitive that passes untrusted input into the `|resize` Twig filter (or the `ResizeImages::resize()` API).** The `/resize/{file}` route itself is a lookup against a cache entry that was previously written by trusted server-side code, and an unauthenticated visitor cannot cause an arbitrary source path to be written into that cache. In October's trust model the Publisher and Developer backend roles that can author templates are already trusted with template code execution, so this is a defense-in-depth hardening rather than an unauthenticated network-to-RCE path. ### Impact - On installations where a template auth
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 4.3.5 for october/october. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-2xmm-m4wv-3fjh ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-100909 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.