Coder up to 2.29.16/2.32.6/2.33.7/2.34.1 Data Upload dataupload.go NewDataBuilder FileSize unrestricted upload

Summaryinfo

A vulnerability described as critical has been identified in Coder up to 2.29.16/2.32.6/2.33.7/2.34.1. Affected is the function NewDataBuilder of the file provisionersdk/proto/dataupload.go of the component Data Upload Handler. Executing a manipulation of the argument FileSize can lead to unrestricted upload. This vulnerability appears as CVE-2026-55079. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Coder up to 2.29.16/2.32.6/2.33.7/2.34.1. It has been declared as critical. This vulnerability affects the function NewDataBuilder of the file provisionersdk/proto/dataupload.go of the component Data Upload Handler. The manipulation of the argument FileSize with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.24.0 and prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `NewDataBuilder` in `provisionersdk/proto/dataupload.go` allocated a byte slice using the client-supplied `FileSize` from a `DataUpload` message without an upper-bound check. Although the DRPC wire limit is 4 MiB, the `FileSize` value itself was unconstrained. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates `FileSize` against an upper bound (`MaxFileSize = 100 MiB`) before allocation. As a workaround, restrict access to the provisioner daemon serve endpoint to trusted provisioner daemon service accounts.

The advisory is available at github.com. This vulnerability was named CVE-2026-55079 since 06/16/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1608.002 by the MITRE ATT&CK project.

Upgrading to version 2.29.17, 2.32.7, 2.33.8 or 2.34.2 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• Coder

Version

• 2.29.0
• 2.29.1
• 2.29.2
• 2.29.3
• 2.29.4
• 2.29.5
• 2.29.6
• 2.29.7
• 2.29.8
• 2.29.9
• 2.29.10
• 2.29.11
• 2.29.12
• 2.29.13
• 2.29.14
• 2.29.15
• 2.29.16
• 2.32.0
• 2.32.1
• 2.32.2
• 2.32.3
• 2.32.4
• 2.32.5
• 2.32.6
• 2.33.0
• 2.33.1
• 2.33.2
• 2.33.3
• 2.33.4
• 2.33.5
• 2.33.6
• 2.33.7
• 2.34.0
• 2.34.1

Website

• Product: https://github.com/coder/coder/

CPE 2.3info

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CPE 2.2info

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