CVE-2026-118574
S3 File System - Moderately critical - Access bypass - SA-CONTRIB-2026-279
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting Incorrectly Configured Access Control Security Levels. This issue affects S3 File System versions: from 0.0.0 to 3.12.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
S3 File System - Moderately critical - Access bypass - SA-CONTRIB-2026-279
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting Incorrectly Configured Access Control Security Levels. This issue affects S3 File System versions: from 0.0.0 to 3.12.0.
- Record
CVE-2026-118574- CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-732
- Updated
- 2026-11-06
EUVDEUVD-2026-113692
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting Incorrectly Configured Access Control Security Levels. This issue affects S3 File System versions: from 0.0.0 to 3.12.0.
- Record
EUVD-2026-113692- CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-06
GitHub AdvisoriesGHSA-vj8c-wmj2-3vg2
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System...
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting Incorrectly Configured Access Control Security Levels. This issue affects S3 File System versions: from 0.0.0 to 3.12.0.
- Record
GHSA-vj8c-wmj2-3vg2- CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-732
- Updated
- 2026-11-06
NVD
Incorrect Permission Assignment for Critical Resource vulnerability in Drupal S3 File System allows Exploiting Incorrectly Configured Access Control Security Levels. This issue affects S3 File System versions: from 0.0.0 to 3.12.0.
- Record
CVE-2026-118574- CVSS 3.1
- 5.6 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-732
- Updated
- 2026-11-06
OSVDRUPAL-CONTRIB-2026-279 No score
S3 File System (s3fs) provides an additional file system to your Drupal site that stores files in Amazon's Simple Storage Service (S3) storage.
The module doesn't sufficiently isolate upload context between separate object(file) operations in the same request resulting in the potential for objects to be uploaded with incorrect access control list (ACL) entries or corruption through incorrect operation metadata.
This vulnerability is mitigated by the fact that an attacker must be able to trigger multiple file operations on S3FS.
Some vectors are mitigated by:
- Not enabling private:// takeover (
$settings['s3fs.use_s3_for_private'] = FALSE;) or only enabled with$settings['s3fs.upload_as_private'] = TRUE; - The deployment does not utilize
hook_s3fs_stream_open_params_alter(),hook_s3fs_upload_params_alter(),hook_s3fs_copy_params_alter(), orhook_s3fs_command_params_alter()
If both points above have always been true, all currently known vectors are mitigated.
- Record
DRUPAL-CONTRIB-2026-279- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
drupal/s3fsPackagist:https://packages.drupal.org/8 |
before 3.12.0 | 3.12.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| severity | CVE List | |
| facts, severity | EUVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-118574 is a medium vulnerability (CVSS 5.6) in Drupal S3 File System, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.15%, the 4th percentile. Fixed in drupal/s3fs 3.12.0.