CVE-2026-34750
Payload has Insufficient Filename Validation in Client-Upload Signed-URL Endpoints
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3, the client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location. This issue has been patched in version 3.78.0 for @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Payload has Insufficient Filename Validation in Client-Upload Signed-URL Endpoints
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3, the client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location. This issue has been patched in version 3.78.0 for @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3.
- Record
CVE-2026-34750- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-18019
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3, the client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location. This issue has been patched in version 3.78.0 for @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3.
- Record
EUVD-2026-18019- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-frq9-7j6g-v74x
Payload has Insufficient Filename Validation in Client-Upload Signed-URL Endpoints
Impact
The client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location.
Consumers are affected if ALL of these are true:
-
Payload version < v3.78.0
-
Using client-upload signed-URL endpoints for any supported storage adapter
Patches
This vulnerability has been patched in v3.78.0. Filename validation has been hardened for client uploads.
Consumers should upgrade to v3.78.0 or later.
Workarounds
Consumers can upgrade:
- Limit access to client-upload signed-URL endpoints to trusted users only.
- Record
GHSA-frq9-7j6g-v74x- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3, the client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location. This issue has been patched in version 3.78.0 for @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3.
- Record
CVE-2026-34750- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Payload has Insufficient Filename Validation in Client-Upload Signed-URL Endpoints
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3, the client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location. This issue has been patched in version 3.78.0 for @payloadcms/storage-azure, @payloadcms/storage-gcs, @payloadcms/storage-r2, and @payloadcms/storage-s3.
- Record
CVE-2026-34750- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVGHSA-frq9-7j6g-v74x
Payload has Insufficient Filename Validation in Client-Upload Signed-URL Endpoints
Impact
The client-upload signed-URL endpoints for S3, GCS, Azure, and R2 did not properly sanitize filenames. An attacker could craft filenames to escape the intended storage location.
Consumers are affected if ALL of these are true:
-
Payload version < v3.78.0
-
Using client-upload signed-URL endpoints for any supported storage adapter
Patches
This vulnerability has been patched in v3.78.0. Filename validation has been hardened for client uploads.
Consumers should upgrade to v3.78.0 or later.
Workarounds
Consumers can upgrade:
- Limit access to client-upload signed-URL endpoints to trusted users only.
- Record
GHSA-frq9-7j6g-v74x- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@payloadcms/storage-azurenpm |
before 3.78.0 | 3.78.0 |
@payloadcms/storage-gcsnpm |
before 3.78.0 | 3.78.0 |
@payloadcms/storage-r2npm |
before 3.78.0 | 3.78.0 |
@payloadcms/storage-s3npm |
before 3.78.0 | 3.78.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-34750 is a medium vulnerability (CVSS 6.5) in Payloadcms Payload, published April 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 29th percentile. Fixed in @payloadcms/storage-azure 3.78.0.