CVE-2026-55078

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

Summary

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.

> Note: Exploitation requires authenticated file-upload access and the impact is limited to availability (denial of service).

Impact

An authenticated user could upload a zip within the 100 MiB upload limit but containing many highly compressible entries whose decompressed size exhausted memory, crashing coderd before any RBAC check. Repeated requests could keep the service unavailable. This is a denial of service; it does not allow data disclosure or code execution.

Patches

The fix adds a metadata preflight check that sums projected entry sizes and a streaming writer that enforces the aggregate limit during decompression.

The fix was backported to all supported release lines:

| Release line | Patched version | |---|---| | 2.34 | v2.34.2 | | 2.33 | v2.33.8 | | 2.32 | v2.32.7 | | 2.29 (ESR) | v2.29.17 |

Workarounds

Restrict file-upload permissions to trusted users or place a reverse proxy with request-body size limits in front of coderd.

Resources

  • Fix: #25877

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22438) for independently disclosing this issue!

CVSS v3
6.5
EG Score
6.5(low)
EPSS
—
KEV
Not listed

Published

July 6, 2026

Last Modified

July 6, 2026

Vendor Advisories for CVE-2026-55078(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 1× in last 7d / 1× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 21:35 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-55078?
CVE-2026-55078 is a medium vulnerability published on July 6, 2026. Coder: Zip upload decompression lacks aggregate size limit, enabling denial of service Summary 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…
When was CVE-2026-55078 disclosed?
CVE-2026-55078 was first published in the National Vulnerability Database on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-55078?
CVE-2026-55078 has a CVSS v4.0 base score of 6.5 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55078?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55078, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-55078

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