CVE-2026-5749 (GCVE-0-2026-5749)
Vulnerability from cvelistv5 – Published: 2026-04-22 13:23 – Updated: 2026-04-22 14:06
VLAI
EPSS
VEX
Title
Inadequate access control vulnerability in Fullstep
Summary
Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-22 14:02 UTC
CWE
- CWE-306 - Missing authentication for critical function
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://www.incibe.es/en/incibe-cert/notices/avis… | patch |
Impacted products
Date Public
2026-04-20 10:00
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-5749",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-22T14:02:34.571025Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T14:06:57.793Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Fullstep",
"vendor": "Fullstep",
"versions": [
{
"status": "affected",
"version": "5"
},
{
"status": "unaffected",
"version": "5.30.07"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:fullstep:fullstep:5:*:*:*:*:*:*:*",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:fullstep:fullstep:5.30.07:*:*:*:*:*:*:*",
"vulnerable": false
}
],
"negate": false,
"operator": "OR"
}
],
"operator": "OR"
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Alejandro Rivera Le\u00f3n"
}
],
"datePublic": "2026-04-20T10:00:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API."
}
],
"value": "Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"exploitMaturity": "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:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-306",
"description": "CWE-306 Missing authentication for critical function",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T13:24:06.620Z",
"orgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
"shortName": "INCIBE"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-fullstep"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "The vulnerability has been fixed by the Fullstep team in version 5.30.07, which has been available in production since January 29, 2026."
}
],
"value": "The vulnerability has been fixed by the Fullstep team in version 5.30.07, which has been available in production since January 29, 2026."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Inadequate access control vulnerability in Fullstep",
"x_generator": {
"engine": "Vulnogram 1.0.1"
}
}
},
"cveMetadata": {
"assignerOrgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
"assignerShortName": "INCIBE",
"cveId": "CVE-2026-5749",
"datePublished": "2026-04-22T13:23:37.971Z",
"dateReserved": "2026-04-07T15:31:14.737Z",
"dateUpdated": "2026-04-22T14:06:57.793Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-5749",
"date": "2026-10-24",
"epss": "0.00419",
"percentile": "0.35148"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Fullstep",
"vendor": "Fullstep",
"versions": [
{
"status": "affected",
"version": "5"
},
{
"status": "unaffected",
"version": "5.30.07"
}
]
}
],
"source": "cve-coordination@incibe.es"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API."
}
],
"id": "CVE-2026-5749",
"lastModified": "2026-06-17T10:59:35.707",
"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:H/VI:N/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": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "cve-coordination@incibe.es",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-5749",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-22T14:02:34.571025Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-04-22T14:17:05.993",
"references": [
{
"source": "cve-coordination@incibe.es",
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-fullstep"
}
],
"sourceIdentifier": "cve-coordination@incibe.es",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-306"
}
],
"source": "cve-coordination@incibe.es",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-06-05T19:19:44+00:00",
"cve": "CVE-2026-5749",
"id": "CVE-2026-5749",
"initial_release_date": "2026-04-20T10:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Inadequate access control vulnerability in Fullstep",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5749.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-5749",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-22T14:02:34.571025Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T14:02:57.631Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Fullstep",
"vendor": "Fullstep",
"versions": [
{
"status": "affected",
"version": "5"
},
{
"status": "unaffected",
"version": "5.30.07"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:fullstep:fullstep:5:*:*:*:*:*:*:*",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:fullstep:fullstep:5.30.07:*:*:*:*:*:*:*",
"vulnerable": false
}
],
"negate": false,
"operator": "OR"
}
],
"operator": "OR"
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Alejandro Rivera Le\u00f3n"
}
],
"datePublic": "2026-04-20T10:00:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API."
}
],
"value": "Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"exploitMaturity": "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:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-306",
"description": "CWE-306 Missing authentication for critical function",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T13:24:06.620Z",
"orgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
"shortName": "INCIBE"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-fullstep"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "The vulnerability has been fixed by the Fullstep team in version 5.30.07, which has been available in production since January 29, 2026."
}
],
"value": "The vulnerability has been fixed by the Fullstep team in version 5.30.07, which has been available in production since January 29, 2026."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Inadequate access control vulnerability in Fullstep",
"x_generator": {
"engine": "Vulnogram 1.0.1"
}
}
},
"cveMetadata": {
"assignerOrgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
"assignerShortName": "INCIBE",
"cveId": "CVE-2026-5749",
"datePublished": "2026-04-22T13:23:37.971Z",
"dateReserved": "2026-04-07T15:31:14.737Z",
"dateUpdated": "2026-04-22T14:06:57.793Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
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.