High
nagios4 — security advisory
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.
- Products
- nagios4
- Affected versions
- 4.3.4-3, 4.3.4-3ubuntu0.1, 4.4.6-4, 4.4.6-4.1ubuntu1, 4.4.6-4.1ubuntu2, 4.4.6-4ubuntu0.22.04.1, 4.4.6-4ubuntu0.24.04.1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-48551
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:06 UTC · Revision 1
Source evidence
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.
osv:UBUNTU-CVE-2026-48551
nagios4
Fixed versions: Not specified
nagios4
Fixed versions: Not specified
nagios4
Fixed versions: Not specified
nagios4
Fixed versions: Not specified
nagios4
Fixed versions: Not specified
Complete source record
{
"id": "6f0f9da3f5a61d60017c193fcabbbc9e733993ca2654b8030043d3067664da57",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-48551",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-48551",
"summary": "Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.",
"evidence": "osv:UBUNTU-CVE-2026-48551",
"products": [
{
"name": {
"value": "nagios4",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.3.4-3",
"evidence": "/affected/0/versions"
},
{
"value": "4.3.4-3ubuntu0.1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
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"affected_versions": [
{
"value": "4.4.6-4",
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{
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{
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{
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"affected_versions": [
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{
"name": {
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"affected_versions": [
{
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"evidence": "/affected/4/versions"
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{
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"evidence": "/affected/4/versions"
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],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-48551",
"aliases": [
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],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
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"purl": "pkg:deb/ubuntu/nagios4?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
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"4.3.4-3ubuntu0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48551.json"
},
"ecosystem_specific": {
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{
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"binary_version": "4.3.4-3ubuntu0.1"
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{
"binary_name": "nagios4-cgi",
"binary_version": "4.3.4-3ubuntu0.1"
},
{
"binary_name": "nagios4-common",
"binary_version": "4.3.4-3ubuntu0.1"
},
{
"binary_name": "nagios4-core",
"binary_version": "4.3.4-3ubuntu0.1"
}
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}
},
{
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"package": {
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"ecosystem": "Ubuntu:22.04:LTS"
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"versions": [
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{
"binary_name": "nagios4-cgi",
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{
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"package": {
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"purl": "pkg:deb/ubuntu/nagios4?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"4.4.6-4",
"4.4.6-4ubuntu0.24.04.1"
],
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},
"ecosystem_specific": {
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"binary_name": "nagios4",
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},
{
"binary_name": "nagios4-cgi",
"binary_version": "4.4.6-4ubuntu0.24.04.1"
},
{
"binary_name": "nagios4-common",
"binary_version": "4.4.6-4ubuntu0.24.04.1"
},
{
"binary_name": "nagios4-core",
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"versions": [
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"database_specific": {
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"ecosystem_specific": {
"binaries": [
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"binary_name": "nagios4",
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},
{
"binary_name": "nagios4-cgi",
"binary_version": "4.4.6-4.1ubuntu2"
},
{
"binary_name": "nagios4-common",
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{
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"package": {
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"purl": "pkg:deb/ubuntu/nagios4?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"4.4.6-4.1ubuntu1",
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],
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},
"ecosystem_specific": {
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"binary_name": "nagios4",
"binary_version": "4.4.6-4.1ubuntu2"
},
{
"binary_name": "nagios4-cgi",
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},
{
"binary_name": "nagios4-common",
"binary_version": "4.4.6-4.1ubuntu2"
},
{
"binary_name": "nagios4-core",
"binary_version": "4.4.6-4.1ubuntu2"
}
]
}
}
],
"modified": "2026-10-17T13:00:21.631001674Z",
"provider": "osv",
"upstream": [
"CVE-2026-48551"
],
"references": [
"https://ubuntu.com/security/CVE-2026-48551",
"https://www.cve.org/CVERecord?id=CVE-2026-48551",
"https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog",
"https://www.nagios.com/security-disclosures/nagios-core/",
"https://www.vulncheck.com/advisories/nagios-core-xi-csrf-protection-bypass-via-double-submit-cookie"
]
},
"related_cves": [
{
"value": "CVE-2026-48551",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360438,
"published_at": "2026-08-12T17:17:00+00:00"
}