Fortinet FortiAuthenticator up to 6.6.10/8.0.3 out-of-bounds write

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.1$0-$5k0.00+

Summaryinfo

A vulnerability classified as very critical has been found in Fortinet FortiAuthenticator up to 6.6.10/8.0.3. Affected by this issue is some unknown functionality. The manipulation leads to out-of-bounds write. This vulnerability is referenced as CVE-2026-126245. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Fortinet FortiAuthenticator up to 6.6.10/8.0.3. It has been rated as very critical. This issue affects some unknown processing. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A out-of-bounds write vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an unauthenticated attacker to execute unauthorized code or commands via http requests, should the attacker be able to defeat ASLR protections.

The advisory is shared at fortiguard.fortinet.com. The identification of this vulnerability is CVE-2026-126245 since 11/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/11/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 9.1

VulDB Base Score: 10.0
VulDB Temp Score: 10.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (fortinet): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

11/10/2026 CVE reserved
11/11/2026 +1 days Advisory disclosed
11/11/2026 +0 days VulDB entry created
11/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: fortinet.com

Advisory: fortiguard.fortinet.com
Status: Confirmed

CNA: fortinet
CVE: CVE-2026-126245 (🔒)

GCVE (CVE): GCVE-0-2026-126245
GCVE (VulDB): GCVE-100-436085

Entryinfo

Created: 11/11/2026 23:03
Changes: 11/11/2026 23:03 (60)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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