Cyber Resilience

CVE-2026-5082

Tokuhirom Amon2\ \

Published
08 April 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0040 33th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-5082 is a medium-severity PRNG (CWE-338) vulnerability in Tokuhirom Amon2\. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 33th 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 IA-5 (Authenticator Management) and SC-13 (Cryptographic Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Amon2::Plugin::Web::CSRFDefender versions from 7.00 through 7.03 for Perl generate an insecure session id. The generate_session_id function will attempt to read bytes from the /dev/urandom device, but if that is unavailable then it generates bytes using SHA-1 hash seeded with the…

more

built-in rand() function, the PID, and the high resolution epoch time. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Amon2::Plugin::Web::CSRFDefender versions before 7.00 were part of Amon2, which was vulnerable to insecure session ids due to CVE-2025-15604. Note that the author has deprecated this module.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
Why these techniques?

Weak/predictable session ID generation (CWE-338/340) directly enables remote prediction of valid web session cookies on a public-facing Perl web app, facilitating exploitation via T1190 and cookie forgery via T1606.001.

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

CVEs Like This One

CVE-2026-3255Same vendor: Tokuhirom
CVE-2025-15604Same vendor: Tokuhirom
CVE-2026-5083Shared CWE-338, CWE-340
CVE-2026-8503Shared CWE-338, CWE-340
CVE-2026-3257Same vendor: Tokuhirom
CVE-2026-3256Shared CWE-338, CWE-340
CVE-2026-5080Shared CWE-338, CWE-340
CVE-2025-40920Shared CWE-338, CWE-340
CVE-2026-56016Shared CWE-338, CWE-340
CVE-2026-9692Shared CWE-338, CWE-340

Affected Assets

tokuhirom
amon2\
\

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-13 Cryptographic Protection
  • IA-5 Authenticator Management
  • SC-23 Session Authenticity
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 9 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V7.2.3
  • V11.5.1
  • V11.3.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Mandates use of FIPS-validated or NSA-approved cryptography, directly preventing weak PRNG fallbacks when generating session IDs.

prevent

Requires cryptographic-quality randomness and sufficient entropy for authenticators such as session identifiers.

prevent

Enforces mechanisms that protect session authenticity, which is defeated by predictable IDs produced by the flawed generate_session_id routine.

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 explicitly require cryptographically strong RNG selection and usage in security contexts.

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.

prevents

Mandates use of approved cryptographic controls, directly requiring cryptographically strong RNGs.

detects

Security testing can detect use of weak random number generators.

prevents

Secure SDLC processes should catch weak PRNG usage during design and code review.

prevents

Application security requirements can specify cryptographically strong random number generation.

prevents

Secure engineering principles include selection of appropriate cryptographic primitives.

prevents

Secure coding standards prohibit use of weak PRNGs in security contexts.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Oracle Linux 8 (1 rule)
  • V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. via CWE-340
RHEL 7 (1 rule)
  • V-204497 The Red Hat Enterprise Linux operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. via CWE-340

References