CVE-2026-58399 (GCVE-0-2026-58399)
Vulnerability from cvelistv5 – Published: 2026-07-01 14:25 – Updated: 2026-07-02 14:26
VLAI
EPSS
VEX
Title
@acastellon/auth has an authentication bypass via spoofable headers in validateToken()
Summary
@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-02 14:25 UTC
CWE
- CWE-287 - Improper Authentication
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/antonio-castellon/module-auth/… | x_refsource_CONFIRM |
| https://github.com/antonio-castellon/module-auth/… | x_refsource_MISC |
| https://www.npmjs.com/package/@acastellon/auth/v/2.3.0 | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| antonio-castellon | module-auth |
Affected:
< 2.3.0
|
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-58399",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-02T14:25:47.187429Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-02T14:26:00.684Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "module-auth",
"vendor": "antonio-castellon",
"versions": [
{
"status": "affected",
"version": "\u003c 2.3.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get(\u0027host\u0027).startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "CWE-287: Improper Authentication",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-01T14:25:44.452Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw"
},
{
"name": "https://github.com/antonio-castellon/module-auth/issues/6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/antonio-castellon/module-auth/issues/6"
},
{
"name": "https://www.npmjs.com/package/@acastellon/auth/v/2.3.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://www.npmjs.com/package/@acastellon/auth/v/2.3.0"
}
],
"source": {
"advisory": "GHSA-gfj5-979r-92pw",
"discovery": "UNKNOWN"
},
"title": "@acastellon/auth has an authentication bypass via spoofable headers in validateToken()"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-58399",
"datePublished": "2026-07-01T14:25:44.452Z",
"dateReserved": "2026-06-30T18:19:58.378Z",
"dateUpdated": "2026-07-02T14:26:00.684Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-58399",
"date": "2026-09-18",
"epss": "0.00973",
"percentile": "0.60488"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "module-auth",
"vendor": "antonio-castellon",
"versions": [
{
"status": "affected",
"version": "\u003c 2.3.0"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get(\u0027host\u0027).startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0."
}
],
"id": "CVE-2026-58399",
"lastModified": "2026-07-02T17:54:15.243",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-58399",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-02T14:25:47.187429Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-01T15:17:11.377",
"references": [
{
"source": "security-advisories@github.com",
"url": "https://github.com/antonio-castellon/module-auth/issues/6"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw"
},
{
"source": "security-advisories@github.com",
"url": "https://www.npmjs.com/package/@acastellon/auth/v/2.3.0"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-287"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-58399",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-02T14:25:47.187429Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-02T14:25:57.146Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "module-auth",
"vendor": "antonio-castellon",
"versions": [
{
"status": "affected",
"version": "\u003c 2.3.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get(\u0027host\u0027).startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "CWE-287: Improper Authentication",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-01T14:25:44.452Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw"
},
{
"name": "https://github.com/antonio-castellon/module-auth/issues/6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/antonio-castellon/module-auth/issues/6"
},
{
"name": "https://www.npmjs.com/package/@acastellon/auth/v/2.3.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://www.npmjs.com/package/@acastellon/auth/v/2.3.0"
}
],
"source": {
"advisory": "GHSA-gfj5-979r-92pw",
"discovery": "UNKNOWN"
},
"title": "@acastellon/auth has an authentication bypass via spoofable headers in validateToken()"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-58399",
"datePublished": "2026-07-01T14:25:44.452Z",
"dateReserved": "2026-06-30T18:19:58.378Z",
"dateUpdated": "2026-07-01T14:25:44.452Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…