Cyber Resilience

CVE-2026-5091

Published
21 May 2026
Modified
23 July 2026
CVSS Score v3.1 5.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0020 10th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-5091 is a medium-severity Observable Timing Discrepancy (CWE-208) vulnerability. Its CVSS base score is 5.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Password Guessing (T1110.001); ranked at the 10th 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 AC-3 (Access Enforcement) and IA-5 (Authenticator Management) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Catalyst::Plugin::Authentication versions through 0.10024 for Perl is susceptible to timing attacks. These versions use Perl's built-in eq comparison. Discrepencies in timing could be used to guess the underlying hash or password.

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 side-channel in authentication comparison directly enables remote password guessing attacks.

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

CVEs Like This One

CVE-2026-6656Shared CWE-208
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-2024-47178Shared CWE-208
CVE-2026-5086Shared CWE-208
CVE-2025-59350Shared CWE-208

Affected Assets

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

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • IA-5 Authenticator Management
  • SC-8 Transmission Confidentiality and Integrity
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

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

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match
prevent

Directly requires secure enforcement of access decisions, which this CVE bypasses via observable timing discrepancies in the eq-based credential check.

IA-5 Authenticator Management partial match
prevent

Mandates proper authenticator verification mechanisms; the plugin's use of non-constant-time comparison violates secure verification of passwords/hashes.

SC-8 Transmission Confidentiality and Integrity minimal match
prevent

Requires protection of authentication data in transit/processing; timing leakage effectively exposes credential secrets during comparison.

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