CVE-2026-55078CWE-409CWE-770

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

Medium · published July 7, 2026

CVSS v3.1
6.5
EPSS
1%
Percentile
48.1
In the wild
Unconfirmed
What it is

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`.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00602 · 48.1th percentile
Weaknesses
CWE-409 · Improper Handling of Highly Compressed Data (Data Amplification); CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-07-07T22:47Z
EPSS history
Timeline
  • 07 JUL 22:47Z
    Coder: Zip upload decompression lacks aggregate size limit, enabling denial of service
    cvelistv5