Nagios XI versions prior to 2024R1.2.2 contain a host header injection vulnerability. The application trusts the user-supplied HTTP Host header when constructing absolute URLs without sufficient validation. An unauthenticated, remote attacker can supply a crafted Host header to poison generated links or responses, which may facilitate phishing of credentials, account recovery link hijacking, and web cache poisoning.
Published: 2025-10-30
Updated: 2025-11-06
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 8.8
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.0016