CVE-2026-123201
Full vulnerability record from the local CVENow database.
Description
Buku (bukuserver) through 5.1.1 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server request internal hosts by supplying a url parameter to /api/fetch_data or /api/network_handle. Attackers can target loopback, private, or cloud metadata IP addresses, which pass the weak is_bad_url() check and follow redirects, to discover internal services and read their page titles, descriptions, and keywords.
Severity
MEDIUM
CVSS score
6.3
(v4.0)
Vulnerability status
Received
Source identifier
Published
2026-11-05 19:17:19.153000
Last modified
2026-11-05 19:17:19.153000
View original CVE JSON
{
"id": "CVE-2026-123201",
"sourceIdentifier": "[email protected]",
"published": "2026-11-05T19:17:19.153",
"lastModified": "2026-11-05T19:17:19.153",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Buku (bukuserver) through 5.1.1 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server request internal hosts by supplying a url parameter to /api/fetch_data or /api/network_handle. Attackers can target loopback, private, or cloud metadata IP addresses, which pass the weak is_bad_url() check and follow redirects, to discover internal services and read their page titles, descriptions, and keywords."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "jarun",
"product": "buku",
"defaultStatus": "unaffected",
"repo": "https://github.com/jarun/buku",
"packageURL": "pkg:pypi/buku",
"versions": [
{
"version": "0",
"lessThanOrEqual": "5.1.1",
"versionType": "custom",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/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",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 3.9,
"impactScore": 1.4
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-918"
}
]
}
],
"references": [
{
"url": "https://github.com/jarun/buku/blob/e232ac357cbba22fe69d6d6dfc0d35512a4cd313/buku.py#L4057-L4084",
"source": "[email protected]"
},
{
"url": "https://github.com/jarun/buku/blob/e232ac357cbba22fe69d6d6dfc0d35512a4cd313/bukuserver/api.py#L97-L105",
"source": "[email protected]"
},
{
"url": "https://github.com/jarun/buku/commit/13f6497afc974f02f1069b760772abe8815d1675",
"source": "[email protected]"
},
{
"url": "https://github.com/jarun/buku/issues/910",
"source": "[email protected]"
},
{
"url": "https://github.com/jarun/buku/pull/916",
"source": "[email protected]"
},
{
"url": "https://www.vulncheck.com/advisories/buku-through-5.1.1-ssrf-via-bukuserver-fetch-data-and-network-handle-api",
"source": "[email protected]"
}
]
}