CVE-2026-25815
Raw vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:NSummary
CVE-2026-25815 is a low-severity Use of Default Cryptographic Key (CWE-1394) vulnerability in Fortinet FortiOS (inferred from references). Its CVSS base score is 3.2 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Private Keys (T1552.004); ranked at the 1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and SC-12 (Cryptographic Key Establishment and Management) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5525
- 🇦🇹 CERT.at: www.cert.at
Vulnerability Data
Fortinet FortiOS through 7.6.6 allows attackers to decrypt LDAP credentials stored in device configuration files, as exploited in the wild from 2025-12-16 through 2026 (by default, the encryption key is the same across all customers' installations). NOTE: the Supplier's position…
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is that the instance of CWE-1394 is not a vulnerability because customers "are supposed to enable" a non-default option that eliminates the weakness. However, that non-default option can disrupt functionality as shown in the "Managing FortiGates with private data encryption" document, and is therefore intentionally not a default option.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Cryptographic key establishment and management requires generating and provisioning unique keys rather than relying on manufacturer defaults.
Requiring the most restrictive configuration settings prohibits the use of known default cryptographic keys.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Configuration management directly prohibits default keys via hardened baselines and change control.
Credential/key management practices eliminate default cryptographic keys for identities and services.
Strong authentication requirements implicitly disallow default keys but do not address key management itself.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Mandates proper key management, directly preventing use of default cryptographic keys.
Enforces secure configuration baselines that should replace default keys.
Controls software installation and configuration, reducing risk of default keys being left in place.
Change-management processes should detect and remediate default cryptographic keys.
Requires secure authentication mechanisms that would be undermined by default keys.