CVE catalog

CVE-2026-48551

nagios4: CVE-2026-48551

Severity: Medium · CVSS 6.1CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:H/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
Published: Aug 12, 2026, 5:17:27 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.26% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	nagios4	sid	`4.5.14+ds-1`	fixed
Debian	nagios4	forky	`4.5.14+ds-1`	fixed
Debian	nagios4	trixie	`4.4.6-4.1+deb13u1`	vulnerable
Debian	nagios4	trixie-security	`4.4.6-4.1+deb13u2`	fixed
Debian	nagios4	bookworm	`4.4.6-4+deb12u1`	vulnerable
Debian	nagios4	bookworm-security	`4.4.6-4+deb12u2`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	nagios4	source	sid	`4.5.14+ds-1`	not yet assigned	Not reported	[1144495]
Debian	nagios4	source	forky	`4.5.14+ds-1`	not yet assigned	Not reported	[1144495]
Debian	nagios4	source	trixie	`4.4.6-4.1+deb13u2`	not yet assigned	Not reported	[1144495]
Debian	nagios4	source	bookworm	`4.4.6-4+deb12u2`	not yet assigned	Not reported	[1144495]

[Debian bug #1144495]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[nagios4]Affected
Details (4)
- 4.4.6-4+deb12u1 · amd64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · amd64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
[nagios4-cgi]Affected
Source package: [nagios4]
Details (4)
- 4.4.6-4+deb12u1 · amd64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · amd64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
[nagios4-common]Affected
Source package: [nagios4]
Details (4)
- 4.4.6-4+deb12u1 · all · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · all · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · all · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · all · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
[nagios4-core]Affected
Source package: [nagios4]
Details (4)
- 4.4.6-4+deb12u1 · amd64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · amd64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm
- 4.4.6-4+deb12u1 · arm64 · bookworm-security
  Affected · Fixed: 4.4.6-4+deb12u2
  dsa · nagios4 · debian · bookworm

Observed: Oct 27, 2026, 7:10:10 AM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)]