CVE-2026-55079
Coder's unbounded memory allocation in provisioner file upload allows authenticated denial of service
Description
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.
CVSS Vector Breakdown
AV:NAttack VectorAC:LAttack ComplexityPR:HPrivileges RequiredUI:NUser InteractionS:UScopeC:NConfidentialityI:NIntegrityA:HAvailabilityWeaknesses
Affected Products
Exploitability
References
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