Fortinet Fortigate Header injection in captive portal authentication form (FG-IR-26-153)

medium Nessus Plugin ID 326770

Synopsis

Fortinet Firewall is missing one or more security-related updates.

Description

The version of Fortigate installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-153 advisory.

- An Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability [CWE-113] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions may allow an attacker able to intercept and modify a user's captive portal authentication request to inject arbitrary headers via crafted HTTP requests. (CVE-2025-62826)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

For 7.2.x / 7.4.x, see vendor advisory. For 7.6.x, upgrade to Fortigate version 7.6.5 or later.

Plugin Details

Severity: Medium

ID: 326770

File Name: fortigate_FG-IR-26-153.nasl

Version: 1.2

Type: Local

Family: Firewalls

Published: 7/14/2026

Updated: 7/15/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS Score Source: CVE-2025-62826

CVSS v3

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:fortinet:fortios

Required KB Items: Host/Fortigate/model, Host/Fortigate/version

Exploit Ease: No known exploits are available

Patch Publication Date: 7/14/2026

Vulnerability Publication Date: 7/14/2026

Reference Information

CVE: CVE-2025-62826

Detections

Analytics