CVE-2026-55078

MEDIUM

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

Title source: cna
STIX 2.1

Description

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`.

References (6)

Core 6
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/pull/25877
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.29.17
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.32.7
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.33.8
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.34.2

Scores

CVSS v3 6.5
EPSS 0.0060
EPSS Percentile 44.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-409 CWE-770
Status published
Products (5)
coder/coder 2.17.0 - 2.29.17
coder/coder >= 2.17.0, < 2.29.17
coder/coder >= 2.30.0, < 2.32.7
coder/coder >= 2.33.0, < 2.33.8
coder/coder >= 2.34.0, < 2.34.2
Published Jul 07, 2026
Tracked Since Jul 08, 2026