CVE-2026-55427

HIGHPre-NVD 8.38.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (38th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
8.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
8.3HIGHmedium confidence
EG Risk
38
EG Risk 38/100

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 (value × EchelonGraph’s weight)
Severity83% × 45%
The EG Score, 8.3 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
38th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

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 advisoryMentions a patch (unverified)

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 pull request

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 rangeFix by version rangeDependents
github.com/coder/coder—
  • every version on: no fix on record
—
github.com/coder/coder/v2—
  • 2.34.0 up to 2.34.2: fixed in 2.34.2
  • 2.33.0 up to 2.33.8: fixed in 2.33.8
  • 2.30.0 up to 2.32.7: fixed in 2.32.7
  • every version up to 2.29.17: fixed in 2.29.17
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 34× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 144 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 44 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  2. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  4. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  5. 2026-10-12 15:55 UTCEG score recompute
  6. 2026-10-11 19:39 UTCEG score recompute
  7. 2026-10-11 16:54 UTCEG score recompute
  8. 2026-10-11 14:17 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  12. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  14. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  15. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  16. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  18. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  19. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  20. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  21. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  22. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  23. 2026-09-28 13:41 UTCEG score recompute
  24. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 37th percentile
Show 75 more
  1. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  2. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  3. 2026-09-23 06:22 UTCEG score recompute
  4. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-09-18 05:58 UTCEG score recompute
  7. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-09-13 23:55 UTCEG score recompute
  12. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-09-13 08:42 UTCEG score recompute
  14. 2026-09-12 03:50 UTCEG score recompute
  15. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  16. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  18. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  19. 2026-09-06 14:10 UTCEG score recompute
  20. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  21. 2026-09-05 23:00 UTCEG score recompute
  22. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  24. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  25. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  26. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  27. 2026-08-30 07:59 UTCEG score recompute
  28. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  29. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  30. 2026-08-27 21:58 UTCEG score recompute
  31. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  32. 2026-08-27 02:06 UTCEG score recompute
  33. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  34. 2026-08-26 13:54 UTCEG score recompute
  35. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  36. 2026-08-24 20:44 UTCEG score recompute
  37. 2026-08-24 09:55 UTCEG score recompute
  38. 2026-08-23 10:26 UTCEG score recompute
  39. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  40. 2026-08-22 01:56 UTCEG score recompute
  41. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  42. 2026-08-21 04:15 UTCEG score recompute
  43. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  44. 2026-08-20 02:25 UTCEG score recompute
  45. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  46. 2026-08-18 22:29 UTCEG score recompute
  47. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  48. 2026-08-17 22:39 UTCEG score recompute
  49. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  50. 2026-08-16 22:44 UTCEG score recompute
  51. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  52. 2026-08-16 11:54 UTCEG score recompute
  53. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  54. 2026-08-15 03:28 UTCEG score recompute
  55. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  56. 2026-08-14 05:38 UTCEG score recompute
  57. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  58. 2026-08-12 21:12 UTCEG score recompute
  59. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  60. 2026-08-11 23:33 UTCEG score recompute
  61. 2026-08-11 01:55 UTCEG score recompute
  62. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  63. 2026-08-09 17:28 UTCEG score recompute
  64. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  65. 2026-08-08 19:51 UTCEG score recompute
  66. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  67. 2026-08-07 22:14 UTCEG score recompute
  68. 2026-08-06 13:47 UTCEG score recompute
  69. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  70. 2026-08-06 02:47 UTCEG score recompute
  71. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  72. 2026-08-05 01:27 UTCEG score recompute
  73. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  74. 2026-08-04 14:36 UTCEG score recompute
  75. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.3% · 18th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-55427?
CVE-2026-55427 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-55427 published?
The CVE record for CVE-2026-55427 was published on July 6, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 8, 2026; the record at its source may have been updated since.
Is CVE-2026-55427 actively exploited?
CVE-2026-55427 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55427?
CVE-2026-55427 has a CVSS base score of 8.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55427?
A fix for CVE-2026-55427 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55427 are linked in the Vendor Advisories panel on this page.

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