Header injection via captive portal response splitting
Published Jul 14, 2026 · Updated Jul 14, 2026
HTTP response splitting in Fortinet FortiOS, FortiProxy, and FortiPAM allows attackers to inject headers via modified captive portal requests. The captive portal authentication handler places CRLF-bearing request data into HTTP response headers without neutralizing line breaks. Exploitation requires interception and modification of a user's authentication request, and the documented consequence is response-header injection only.
Summary
What happened
HTTP response splitting in Fortinet FortiOS, FortiProxy, and FortiPAM allows attackers to inject headers via modified captive portal requests. The captive portal authentication handler places CRLF-bearing request data into HTTP response headers without neutralizing line breaks. Exploitation requires interception and modification of a user's authentication request, and the documented consequence is response-header injection only.
The record
- CVE
- CVE-2025-62826
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- Fortinet
- Product
- FortiOS
- Classifications
- CWE-113, T1659
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=6.4.0 <=6.4.16
- Affected versionversion=7.0.0 <=7.0.19
- Affected versionversion=7.2.0 <=7.2.13
- Affected versionversion=7.4.0 <=7.4.8
- Affected versionversion=7.6.0 <=7.6.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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