Critical
LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion
Type: advisorySources: OSV
LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-86426
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 18:04 UTC · Revision 1
Source evidence
LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion
core-osv · Original sourcePublished 7 Sept 2026, 12:53 UTC
LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.
osv:CVE-2026-86426
Complete source record
{
"id": "ddb84484450dd55a986ac9b580b4fb0f271d3e6c5040035b585be3ae6aeae0ca",
"url": "https://osv.dev/vulnerability/CVE-2026-86426",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion",
"summary": "LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.",
"evidence": "osv:CVE-2026-86426",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2026-86426",
"aliases": [
"CVE-2026-86426",
"GHSA-cvq8-gqfq-3mvg"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/librenms/librenms",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "d2b6e2557b637a606612959e6007150c3726fb43"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "26.8.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "26.8.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"26.7.0",
"26.6.0",
"26.5.1",
"26.5.0",
"26.4.1",
"26.4.0",
"26.3.1",
"26.3.0",
"26.2.0",
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"25.12.0",
"25.11.0",
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"25.3.0",
"25.2.0",
"25.1.0",
"24.12.0",
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"24.7.0",
"24.6.0",
"24.5.0",
"24.4.1",
"24.4.0",
"24.3.0",
"24.2.0",
"24.1.0",
"23.11.0",
"23.10.0",
"23.9.1",
"23.9.0",
"23.8.2",
"23.8.1",
"23.8.0",
"23.7.0",
"23.6.0",
"23.5.0",
"23.4.1",
"23.4.0",
"23.2.0",
"23.1.0",
"22.12.0",
"22.11.0",
"22.10.0",
"22.9.0",
"22.8.0",
"22.7.0",
"22.6.0",
"22.5.0",
"22.4.0",
"22.3.0",
"22.2.1",
"22.2.0",
"22.1.0",
"21.12.1",
"21.12.0",
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"21.10.0",
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"21.8.0",
"21.7.0",
"21.6.0",
"21.5.1",
"21.5.0",
"21.4.0",
"21.3.0",
"21.2.0",
"21.1.0",
"1.70.1",
"1.70.0",
"1.69",
"1.68",
"1.67",
"1.66",
"1.65",
"1.64.1",
"1.64",
"1.63",
"1.62",
"1.61",
"1.60",
"1.59",
"1.58.1",
"1.58",
"1.57",
"1.56",
"1.55",
"1.54",
"1.53.1",
"1.53",
"1.52",
"1.51",
"1.50",
"1.49",
"1.48.1",
"1.48",
"1.47",
"1.46",
"1.45",
"1.44",
"1.43",
"1.42.01",
"1.42",
"1.41",
"1.40",
"1.39",
"1.38",
"1.37",
"1.36",
"1.35",
"1.33",
"1.32",
"1.31.03",
"1.31.02",
"1.31.01",
"1.28",
"1.27",
"1.26",
"1.25",
"1.21",
"201609",
"1.20",
"20160828",
"1.19",
"201608",
"201607",
"201606",
"201605",
"201604",
"201603",
"201602",
"201601",
"201512",
"201511",
"201510",
"201509",
"201508",
"201507",
"201505",
"201506",
"0.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86426.json"
}
}
],
"modified": "2026-10-28T02:30:30.997386818Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86426.json",
"https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86426",
"https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion"
],
"provider_metadata": {
"cwe_ids": [
"CWE-287"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86426.json"
}
},
"related_cves": [
{
"value": "CVE-2026-86426",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 498146,
"published_at": "2026-09-07T12:53:47.884+00:00"
}