CVE-2026-55438
Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the unverified username in the hostname.
Leer descripción completaMostrar menos
Practical exploitation requires subdomain app routing (wildcard hostname) enabled and a victim who visits the attacker's crafted app URL while authenticated. The fix in versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2 validates the subdomain username against the resolved workspace's actual owner and bases the same-owner CORS decision on the authoritative owner identity. No known workarounds are available.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
- Puntuación base: 6.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.22%
- Percentil entre todas las CVEs puntuadas: 12
- Fecha de la puntuación: 3/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-346
Referencias
- https://github.com/coder/coder/pull/26085
- https://github.com/coder/coder/pull/26086
- https://github.com/coder/coder/releases/tag/v2.29.17
- https://github.com/coder/coder/releases/tag/v2.32.7
- https://github.com/coder/coder/releases/tag/v2.33.8
- https://github.com/coder/coder/releases/tag/v2.34.2
- https://github.com/coder/coder/security/advisories/GHSA-5wg6-jmq2-53pw
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-55438",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-55438",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-07-08T16:56:25.900709Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 5.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 4,
"exploitabilityScore": 1.3
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 6.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 4,
"exploitabilityScore": 2.3
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "coder",
"product": "coder",
"versions": [
{
"status": "affected",
"version": ">= 2.34.0, < 2.34.2"
},
{
"status": "affected",
"version": ">= 2.33.0, < 2.33.8"
},
{
"status": "affected",
"version": ">= 2.30.0, < 2.32.7"
},
{
"status": "affected",
"version": "< 2.29.17"
}
]
}
]
}
],
"published": "2026-07-08T01:16:28.150",
"references": [
{
"url": "https://github.com/coder/coder/pull/26085",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/pull/26086",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/releases/tag/v2.29.17",
"tags": [
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/releases/tag/v2.32.7",
"tags": [
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/releases/tag/v2.33.8",
"tags": [
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/releases/tag/v2.34.2",
"tags": [
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/coder/coder/security/advisories/GHSA-5wg6-jmq2-53pw",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-346"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the unverified username in the hostname. Practical exploitation requires subdomain app routing (wildcard hostname) enabled and a victim who visits the attacker's crafted app URL while authenticated. The fix in versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2 validates the subdomain username against the resolved workspace's actual owner and bases the same-owner CORS decision on the authoritative owner identity. No known workarounds are available."
}
],
"lastModified": "2026-07-08T19:38:38.473",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*",
"vulnerable": true,
"matchCriteriaId": "F97FAF48-192E-4814-82A5-085C44F1D261",
"versionEndExcluding": "2.29.17"
},
{
"criteria": "cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*",
"vulnerable": true,
"matchCriteriaId": "7ABD4A9B-6AE8-47D8-A1B7-91E42EE0481B",
"versionEndExcluding": "2.32.7",
"versionStartIncluding": "2.30.0"
},
{
"criteria": "cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*",
"vulnerable": true,
"matchCriteriaId": "F759EEF3-6EAE-475B-85F8-38E7D7B47438",
"versionEndExcluding": "2.33.8",
"versionStartIncluding": "2.33.0"
},
{
"criteria": "cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*",
"vulnerable": true,
"matchCriteriaId": "397A02BF-6CF6-40B1-B792-D7CB9D229050",
"versionEndExcluding": "2.34.2",
"versionStartIncluding": "2.34.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}