CVE-2025-62826: An Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability [CWE-11

Q: How do I fix CVE-2025-62826?

fortiproxy: upgrade to 7.6.5; fortios: upgrade to 7.6.5. Exact commands for each OS are on this page.

Q: Is CVE-2025-62826 being exploited?

CVE-2025-62826 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-62826 affect?

CVE-2025-62826 affects fortiproxy, fortios. Severity is low (CVSS 3.1). 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 thr

Q: How urgent is CVE-2025-62826?

Priority 19/100. No elevated risk signals yet.

Routine

LOW 3.1UPGRADEUPGRADE

CVE-2025-62826 is a low-severity flaw (CVSS 3.1) affecting fortiproxy, fortios. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 HTT

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	3.1 (Low)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 69%)
CISA exploited list	No
Weakness	CWE-113
Published	2026-07-14
Last modified	2026-09-29

Publisher (CNA): Fortinet, Inc. · Vendor: fortinet

Last updated 2026-09-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 16:16 UTCPublished CVE record published
2026-09-29 15:10 UTCUpdated Record last modified

fortinet fortiproxy UPGRADE

Affected: >= 7.2.0 and < 7.6.5

Fixed in: 7.6.5

Safe to downgrade to: a release before 7.2.0

1. Check installed version

apt-cache policy fortiproxy || rpm -q fortiproxy || fortiproxy --version

2. UPGRADE to 7.6.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fortiproxy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fortiproxy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.2.0 (Debian / Ubuntu)

apt-cache madison fortiproxy sudo apt install fortiproxy=<VERSION_BEFORE_7.2.0> sudo apt-mark hold fortiproxy

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list fortiproxy sudo dnf downgrade fortiproxy-<VERSION_BEFORE_7.2.0> sudo dnf versionlock add fortiproxy

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

fortinet fortios UPGRADE

Affected: >= 7.2.0 and < 7.6.5

Fixed in: 7.6.5

Safe to downgrade to: a release before 7.2.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-62826?

fortiproxy: upgrade to 7.6.5; fortios: upgrade to 7.6.5. Exact commands for each OS are on this page.

Is CVE-2025-62826 being exploited?

CVE-2025-62826 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-62826 affect?

CVE-2025-62826 affects fortiproxy, fortios. Severity is low (CVSS 3.1). 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 thr

How urgent is CVE-2025-62826?

Priority 19/100. No elevated risk signals yet.

Software pages

Fortinet FortiOS vulnerabilities · Fortinet vulnerabilities

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References

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