An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7…

published 2026-02-10 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-207443

cvss: 5.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits: 0; none known

An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header

Patch / fix

fixed in 1

fortinet fortios 7.4.10

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-071-02 updated 2026-05-14 cvss 5.8

Siemens RUGGEDCOM APE1808 Devices

Siemens RUGGEDCOM APE1808
affected: fixed in V7.4.10

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 8 mo ago (2026-02-11)

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.2	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA	3.1	5.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Affected products

Fortinet FortiOS
Siemens RUGGEDCOM APE1808

Classification

Weakness

CWE-444 Inconsistent Interpretation of HTTP Requests

Technology feeds

Fortinet rss critical rss

References

fortiguard.fortinet.com /psirt/FG-IR-25-667
vendor-advisory
cert-portal.siemens.com /productcert/html/ssa-975644.html

Sources

CVE List CVE-2025-55018
NVD CVE-2025-55018

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary