VulnerabilityPublished 9 Dec 2025Updated 14 Jan 2026

CVE-2025-57823: Fortinet FortiAuthenticator · Information Disclosure

Affects Fortinet FortiAuthenticatorSource CVE Database V5

Public exploit available · CVSS 2.6 Low.

Data as of 26 Oct 2026, 11:07 UTC

CVSS 3.1 base score

2.6Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N/E:P/RL:U/RC:C

Base metrics

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Temporal metrics

Exploit Code Maturity: Proof-of-Concept
Remediation Level: Unavailable
Report Confidence: Confirmed

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.
Exploit Code Maturity: Proof-of-Concept: Proof-of-concept exploit code is available, or an attack demonstration is not practical for most systems. The code or technique is not functional in all situations and may require substantial modification by a skilled attacker.
Remediation Level: Unavailable: There is either no solution available or it is impossible to apply.
Report Confidence: Confirmed: Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Fortinet FortiAuthenticator	Affected 6.3.0 – 6.6.0 4 affected builds	Fixed in–

AI-suggested

To mitigate CVE-2025-57823, European organizations should implement the following specific measures: 1) Restrict sponsor-level permissions strictly to trusted personnel and regularly review user roles to minimize the number of accounts with elevated access. 2) Monitor FortiAuthenticator access logs for unusual or unauthorized attempts to access log endpoints, focusing on sponsor accounts. 3) Employ network segmentation and access controls to limit administrative interface exposure to trusted networks and VPNs only. 4) Once Fortinet releases patches or updates addressing this vulnerability, prioritize timely deployment after testing in controlled environments. 5) Consider implementing multi-factor authentication (MFA) for all administrative accounts to reduce the risk of credential compromise. 6) Conduct regular security audits and penetration tests focusing on authentication systems to detect potential abuse of permissions. 7) If possible, disable or restrict access to log download endpoints for sponsor roles until patches are applied. These targeted actions go beyond generic advice by focusing on permission management, monitoring, and access control specific to FortiAuthenticator environments.

Description

A direct request ('forced browsing') vulnerability in Fortinet FortiAuthenticator 6.6.0 through 6.6.6, FortiAuthenticator 6.5 all versions, FortiAuthenticator 6.4 all versions, FortiAuthenticator 6.3 all versions may allow an authenticated attacker with at least sponsor permissions to read and download device logs via accessing specific endpoints

Impact

For European organizations, the primary impact of CVE-2025-57823 is the potential unauthorized disclosure of sensitive log data within FortiAuthenticator devices. Logs may contain information about authentication attempts, user identities, system configurations, and security events, which could be leveraged by attackers for reconnaissance or to plan subsequent attacks. Although the vulnerability requires authenticated access with sponsor permissions, insider threats or compromised sponsor accounts could exploit this flaw. Exposure of logs could also violate data protection regulations such as GDPR if personal data is contained within logs. The impact on operational security is moderate, as attackers gaining insight into authentication systems could attempt privilege escalation or lateral movement. However, since the vulnerability does not affect system integrity or availability, direct disruption of services is unlikely. Organizations relying heavily on FortiAuthenticator for critical identity and access management functions should consider this vulnerability a risk to confidentiality and audit integrity.

References

fortiguard.fortinet.com/psirt/FG-IR-25-554 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Jan 2026, 14:49 UTC

Technical details

References

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