Cyber Resilience

CVE-2026-6656

Published
20 July 2026
Modified
20 July 2026
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0032 24th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-6656 is a high-severity Observable Timing Discrepancy (CWE-208) vulnerability. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Password Guessing (T1110.001); ranked at the 24th 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 SA-8 (Security and Privacy Engineering Principles) and SC-13 (Cryptographic Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Crypt::Password versions through 0.28 for Perl are susceptible to timing attacks. The check_password method uses the built-in eq operator. This allows discrepancies in timing to be used to guess the underlying hash.

CWE(s)
CWE-208

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
Why these techniques?

Timing attack on password comparison directly enables more efficient password guessing against the check_password function.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1110.001 Password Guessing Credential Accessconfidence: MEDIUM
Timing side-channel on password comparison enables efficient password guessing.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-33129Shared CWE-208
CVE-2026-56764Shared CWE-208
CVE-2026-47373Shared CWE-208
CVE-2025-70949Shared CWE-208
CVE-2026-47784Shared CWE-208
CVE-2026-43514Shared CWE-208
CVE-2026-5091Shared CWE-208
CVE-2024-47178Shared CWE-208
CVE-2026-5086Shared CWE-208
CVE-2025-59350Shared CWE-208

Affected Assets

—
Password
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-13 Cryptographic Protection
  • SA-8 Security and Privacy Engineering Principles
  • SI-7 Software, Firmware, and Information Integrity
Detect
Catch it (NIST detect / respond)
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V11.2.4

Mitigating Controls (NIST 800-53 r5) AI

SC-13 Cryptographic Protection good match
prevent

Mandates use of approved cryptographic implementations that must employ constant-time comparison for password hash verification to eliminate timing side-channels.

SA-8 Security and Privacy Engineering Principles good match
prevent

Requires application of secure engineering principles such as constant-time algorithms during design and implementation of authentication functions.

SI-7 Software, Firmware, and Information Integrity partial match
preventdetect

Ensures integrity verification of software components performing sensitive comparisons, detecting or blocking use of non-constant-time operators like eq.

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 constant-time implementations that eliminate observable timing discrepancies.

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.8.17 Clock synchronization none match
none

Consistent reference clocks limit the attacker's ability to measure or manipulate timing differences that could reveal internal state or processing paths.

References