CVE
A missing authentication for critical function vulnerability in Fortinet FortiOS 8.0.0, FortiOS 7.6.0 through 7.6.7, FortiOS 7.4.0 through…
Affects FortiOS 8.0.0, 7.6.0–7.6.7, 7.4.0–7.4.12, 7.2.0–7.2.13 and all 7.0 versions when HA FGSP with standalone-config-sync or autoscale is used. Fixed in 7.6.8; 7.0 has no fixed release.
Written by anthropic/claude-sonnet-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 7.6.8
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. FortiOS 8.0.0, 7.6.0–7.6.7, 7.4.0–7.4.12, 7.2.0–7.2.13, or any 7.0 version HA FGSP with standalone-config-sync, or autoscale, in use
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 35/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Fortinet FortiOS is missing an authentication check on a critical function, which lets an attacker run commands as the super admin by sending crafted high-availability (HA) packets. The attacker can do this remotely without logging in, but only on devices using HA FGSP with standalone-config-sync or autoscale setups.
Read the original description
A missing authentication for critical function vulnerability in Fortinet FortiOS 8.0.0, FortiOS 7.6.0 through 7.6.7, FortiOS 7.4.0 through 7.4.12, FortiOS 7.2.0 through 7.2.13 may allow an unauthenticated attacker with HA FGSP + standalone-config-sync, or autoscale to execute command as super admin via crafted HA packets.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach14/20Affects Fortinet (an enterprise product or network appliance)
- Severity9/10CVSS 9.0
- No patch0/5No signal
What would change the score
- Would score about 85 if added to CISA KEV
- Would score about 80 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
FortiOS 8.0.0, 7.6.0–7.6.7, 7.4.0–7.4.12, 7.2.0–7.2.13, or any 7.0 version HA FGSP with standalone-config-sync, or autoscale, in useUpgrade to a fixed version: 7.6.8.
Workaround: A virtual patch named FG-VD-61445.0day is available in FMWP db update 26.082. FortiOS 7.0 has no fixed release; migrate to a fixed release.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-126259 (A missing authentication for critical function vulnerability in Fortinet FortiOS 8.0.0, FortiOS 7.6.0 through 7.6.7, FortiOS 7.4.0 through…), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-126259 (entry last updated 2026-11-11):
Affected:
- Fortinet FortiOS: from 7.6.0, through 7.6.7; from 7.4.0, through 7.4.12; from 7.2.0, through 7.2.13; from 7.0.0, through 7.0.19
Fixed versions: 7.6.8.
Conditions (all must be true for the bug to be hit):
- FortiOS 8.0.0, 7.6.0–7.6.7, 7.4.0–7.4.12, 7.2.0–7.2.13, or any 7.0 version (source: https://fortiguard.fortinet.com/psirt/FG-IR-26-273)
- HA FGSP with standalone-config-sync, or autoscale, in use (source: https://fortiguard.fortinet.com/psirt/FG-IR-26-273)
Setup: the bug needs a feature or setting that is off by default or uncommon. Check whether each asset has it on.
Attacker needs: network access, no login, no user action.
Workaround: A virtual patch named FG-VD-61445.0day is available in FMWP db update 26.082. FortiOS 7.0 has no fixed release; migrate to a fixed release. (source: https://www.cve.org/CVERecord?id=CVE-2026-126259)
CISA KEV: CVE-2026-126259 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126259 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://fortiguard.fortinet.com/psirt/FG-IR-26-273
- https://www.cve.org/CVERecord?id=CVE-2026-126259
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-126259
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-126259"}.Timeline
- CVE published
- First seen by cve.now1 day
- Posted on X by cve.now
Affected versions
- Fortinet FortiOS
From 7.6.0 · through 7.6.7; From 7.4.0 · through 7.4.12; From 7.2.0 · through 7.2.13; From 7.0.0 · through 7.0.19
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Link
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-126259
Is CVE-2026-126259 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A critical function on the device does not require authentication. An unauthenticated attacker could use crafted HA packets to run commands as super admin on the device.Source: fortiguard.fortinet.com, cve.org
Which versions are affected by CVE-2026-126259?
FortiOS: from 7.6.0 through 7.6.7; from 7.4.0 through 7.4.12; from 7.2.0 through 7.2.13; from 7.0.0 through 7.0.19.Source: cve.now feed data
Am I affected, and how do I check?
Affected are FortiOS 8.0.0, 7.6.0 through 7.6.7, 7.4.0 through 7.4.12, 7.2.0 through 7.2.13, and any 7.0 version. The setup must use HA FGSP with standalone-config-sync, or autoscale. Check the installed FortiOS version and whether those HA settings are configured.Source: fortiguard.fortinet.com, cve.org
How do I fix CVE-2026-126259?
Upgrade to FortiOS 7.6.8 or above. FortiOS 7.0 has no fixed release, so migrate to a fixed release. A virtual patch named FG-VD-61445.0day is available in FMWP db update 26.082.Source: fortiguard.fortinet.com, cve.org