CVE-2026-55078 PUBLISHED

Coder: Zip upload decompression lacks aggregate size limit, enabling denial of service

Assigner: GitHub_M
Reserved: 16.06.2026 Published: 07.07.2026 Updated: 08.07.2026

Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.17.0 and prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, POST /api/v2/files converts zip uploads to tar in memory via CreateTarFromZip, which enforced a per-entry size limit but no aggregate limit on total decompressed output, writing to an unbounded in-memory buffer. Exploitation requires authenticated file-upload access and the impact is limited to availability (denial of service). The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 adds a metadata preflight check that sums projected entry sizes and a streaming writer that enforces the aggregate limit during decompression. As a workaround, restrict file-upload permissions to trusted users or place a reverse proxy with request-body size limits in front of coderd.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 6.5

Product Status

Vendor coder
Product coder
Versions
  • Version >= 2.34.0, < 2.34.2 is affected
  • Version >= 2.33.0, < 2.33.8 is affected
  • Version >= 2.30.0, < 2.32.7 is affected
  • Version >= 2.17.0, < 2.29.17 is affected

References

Problem Types

  • CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) CWE
  • CWE-770: Allocation of Resources Without Limits or Throttling CWE