CVE-2026-55427

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% of all CVEs by exploit prediction. 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: epss, secondary
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.3Exploit: None knownExposed: 0

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

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, coder config-ssh wrote server-supplied SSH settings (HostnameSuffix, SSHConfigOptions) into the user's ~/.ssh/config without sanitizing embedded newlines or restricting directives so a malicious or compromised Coder server could inject arbitrary SSH configuration. Practical exploitation requires control of the server-supplied values through a malicious or compromised deployment, a man-in-the-middle position or admin access to the HostnameSuffix and SSHConfigOptions settings. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates HostnameSuffix and SSHConfigOptions against a strict character set that rejects newlines and other control characters. As a workaround, inspect coder config-ssh --dry-run output before applying changes.

CVSS v3
8.3
EG Score
8.3(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity83% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 8, 2026

Advisory Details (6)

Auto-updated Jul 8, 2026
Patch available. Sources: github_pr, github_release, github.
github Patch Available

SSH config injection via unsanitized server-supplied values in `coder config-ssh` · Advisory · coder/coder · GitHub

https://github.com/coder/coder/security/advisories/GHSA-mcqq-fqgf-rxwm
github_release Patch Available

v2.34.2 [SECURITY]

Patch available: coder/coder v2.34.2

https://github.com/coder/coder/releases/tag/v2.34.2
github_release Patch Available

v2.33.8 [SECURITY]

Patch available: coder/coder v2.33.8

https://github.com/coder/coder/releases/tag/v2.33.8
github_release Patch Available

v2.32.7 [SECURITY]

Patch available: coder/coder v2.32.7

https://github.com/coder/coder/releases/tag/v2.32.7
github_release Patch Available

v2.29.17 [SECURITY]

Patch available: coder/coder v2.29.17

https://github.com/coder/coder/releases/tag/v2.29.17
github_pr

fix!: validate HostnameSuffix and SSHConfigOptions'

Fix merged in coder/coder PR #26154 on 2026-06-10 — awaiting tagged release

https://github.com/coder/coder/pull/26154

Vendor Advisories for CVE-2026-55427(1)

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

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/coder/coder———
github.com/coder/coder/v2—2.34.2—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 33× 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. 2026-07-28 18:58 UTCEG score recompute
  2. 2026-07-28 15:37 UTCEPSS rescore
  3. 2026-07-27 21:14 UTCEG score recompute
  4. 2026-07-26 23:36 UTCEG score recompute
  5. 2026-07-26 14:54 UTCEPSS rescore
  6. 2026-07-26 12:46 UTCEG score recompute
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-24 14:18 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 03:20 UTCEG score recompute
  11. 2026-07-22 14:08 UTCEPSS rescore
  12. 2026-07-21 15:25 UTCEPSS rescore
  13. 2026-07-20 17:08 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-19 14:31 UTCEPSS rescore
  16. 2026-07-19 02:29 UTCEPSS rescore
  17. 2026-07-18 10:04 UTCEPSS rescore
  18. 2026-07-16 17:03 UTCEPSS rescore
  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 16:57 UTCEPSS rescore
  21. 2026-07-15 02:00 UTCEPSS rescore
  22. 2026-07-15 02:00 UTCEPSS rescore
  23. 2026-07-13 22:31 UTCEPSS rescore
  24. 2026-07-13 06:13 UTCEPSS rescore
  25. 2026-07-13 06:13 UTCEPSS rescore
Show 8 more
  1. 2026-07-12 05:46 UTCEPSS rescore
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-09 19:10 UTCEPSS rescore
  6. 2026-07-08 15:16 UTCEPSS rescore
  7. 2026-07-08 15:16 UTCEPSS rescore
  8. 2026-07-06 21:35 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55427?
CVE-2026-55427 is a high vulnerability published on July 6, 2026. Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, coder config-ssh wrote server-supplied SSH settings (HostnameSuffix, SSHConfigOptions) into the user's ~/.ssh/config without sanitizing embedded newlines or…
When was CVE-2026-55427 disclosed?
CVE-2026-55427 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55427 actively exploited?
CVE-2026-55427 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.4% of all scored CVEs.
What is the CVSS score of CVE-2026-55427?
CVE-2026-55427 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-55427?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55427, 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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