CVE-2026-55079

MEDIUMPre-NVD 4.94.9
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 4.9 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
4.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 4.9Exploit: NoneExposed: 0

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

Coder's unbounded memory allocation in provisioner file upload allows authenticated denial of service

Summary

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

Impact

An authenticated user able to reach the provisioner daemon serve endpoint could send a roughly 50-byte message declaring a huge FileSize (for example 1 TiB), triggering an unrecoverable Go out-of-memory abort that terminates coderd. This is a single-message denial of service affecting the entire deployment.

Patches

The fix validates FileSize against an upper bound (MaxFileSize = 100 MiB) before allocation.

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 access to the provisioner daemon serve endpoint to trusted provisioner daemon service accounts.

Resources

  • Fix: #25710

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22442) for independently disclosing this issue!

CVSS v3
4.9
EG Score
4.9(low)
EPSS
—
KEV
Not listed

Published

July 6, 2026

Last Modified

July 6, 2026

Vendor Advisories for CVE-2026-55079(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-2026-55079?
CVE-2026-55079 is a medium vulnerability published on July 6, 2026. Coder's unbounded memory allocation in provisioner file upload allows authenticated denial of service Summary 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…
When was CVE-2026-55079 disclosed?
CVE-2026-55079 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-2026-55079?
CVE-2026-55079 has a CVSS v4.0 base score of 4.9 (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-2026-55079?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55079, 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

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