Cyber Resilience

CVE-2026-6420

Published
06 May 2026
Modified
24 June 2026
CVSS Score v3.1 6.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L
EPSS Score 0.0012 2th percentile
Risk Priority 44 floored blend · peak EPSS

Summary

CVE-2026-6420 is a medium-severity Use of Predictable Algorithm in Random Number Generator (CWE-1241) vulnerability. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked at the 2th 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 SC-13 (Cryptographic Protection) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

A flaw was found in Keylime. An attacker with root access on an enrolled monitored machine, where the Keylime agent runs, can exploit a vulnerability in the Keylime verifier. The verifier uses a hardcoded challenge nonce for Trusted Platform Module…

more

(TPM) quote attestation instead of a cryptographically random value. This allows the attacker to stockpile valid TPM quotes and replay them to evade detection after compromising the system. This issue affects only the push model deployment.

CWE(s)
CWE-1241

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1558 Steal or Forge Kerberos Tickets Credential Access
Adversaries may attempt to subvert Kerberos authentication by stealing or forging Kerberos tickets to enable [Pass the Ticket](https://attack.
attack.mitre.org →
T1606 Forge Web Credentials Credential Access
Adversaries may forge credential materials that can be used to gain access to web applications or Internet services.
attack.mitre.org →
T1649 Steal or Forge Authentication Certificates Credential Access
Adversaries may steal or forge certificates used for authentication to access remote systems or resources.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-13079Shared CWE-1241
CVE-2023-4695Shared CWE-1241
CVE-2025-32056Shared CWE-1241
CVE-2026-57869Shared CWE-1241
CVE-2026-26018Shared CWE-1241

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.5.3
  • V7.2.3
  • V11.5.1
  • V11.5.2

Mitigating Controls (NIST 800-53 r5) AI

SC-13 Cryptographic Protection good match

Specifying required cryptographic mechanisms and algorithms precludes predictable RNG implementations.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require selection of cryptographically secure RNG algorithms instead of predictable ones.

SC-12 Cryptographic Key Establishment and Management partial match

Cryptographic key establishment and management mandates use of unpredictable random values for key material.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require cryptographically strong RNGs, preventing predictable algorithms at design time.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect predictable RNG behavior before deployment.

A.8.24 Use of cryptography partial match
prevents

Mandates use of approved cryptographic algorithms and RNGs, directly preventing predictable PRNGs.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC requires vetted RNG components, reducing likelihood of predictable algorithms.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure engineering principles include selection of cryptographically strong random number generators.

A.8.28 Secure coding partial match
prevents

Secure coding standards prohibit use of weak or predictable RNG functions.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248600 OL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-1241
  • V-248563 The OL 8 SSH server must be configured to use strong entropy. prevents CWE-1241
RHEL 8 (2 rules)
  • V-230253 RHEL 8 must ensure the SSH server uses strong entropy. prevents CWE-1241
  • V-244527 RHEL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-1241

References