CVE-2026-75870
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-75870 is a critical-severity Use of Default Cryptographic Key (CWE-1394) vulnerability. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 41th 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-2026-64294
Vulnerability Data
Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is declared without a secret. The session keyword freezes its options onto the application as given: it does not require a…
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secret, warn, or refuse to start when one is absent. The cookie read and the write-back both default that key to the empty string, so a declaration with no secret option, or with an undefined or empty one, signs and verifies with a zero-length HMAC-SHA256 key. An attacker who knows the cookie format can then mint one offline carrying any contents the session holds, such as a user identifier or a role. Nothing marks the misconfiguration at runtime: cookies are well formed and sessions round-trip as expected.
- 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.
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.
Configuration management directly prohibits default keys via hardened baselines and change control.
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.
Controls software installation and configuration, reducing risk of default keys being left in place.
Mandates proper key management, directly preventing use of default cryptographic keys.
Change-management processes should detect and remediate default cryptographic keys.
Enforces secure configuration baselines that should replace default keys.