Cyber Resilience

CVE-2026-5080

Perldancer Dancer\ \

Published
30 April 2026
Modified
05 May 2026
Patch / advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0036 29th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-5080 is a medium-severity PRNG (CWE-338) vulnerability in Perldancer Dancer\. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29th 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-23 (Session Authenticity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Dancer::Session::Abstract versions through 1.3522 for Perl generates session ids insecurely. The session id is generated from summing the character codepoints of the absolute pathname with the process id, the epoch time and calls to the built-in rand() function to return…

more

a number between 0 and 999-billion, and concatenating that result three times. The path name might be known or guessed by an attacker, especially for applications known to be written using Dancer with standard installation locations. The epoch time can be guessed by an attacker, and may be leaked in the HTTP header. The process id comes from a small set of numbers, and workers may have sequential process ids. The built-in rand() function is seeded with 32-bits and is considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.

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.
Why these techniques?

Insecure session ID generation in a Perl web framework directly enables attackers to predict and hijack sessions on public-facing applications, mapping to exploitation of exposed web apps.

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

CVEs Like This One

CVE-2025-40920Shared CWE-338, CWE-340
CVE-2026-3255Shared CWE-338, CWE-340
CVE-2026-5083Shared CWE-338, CWE-340
CVE-2025-40926Shared CWE-338, CWE-340
CVE-2025-40932Shared CWE-338, CWE-340
CVE-2026-5082Shared CWE-338, CWE-340
CVE-2026-2439Shared CWE-338, CWE-340
CVE-2024-40762Shared CWE-338
CVE-2026-8503Shared CWE-338, CWE-340
CVE-2026-11832Shared CWE-338

Affected Assets

perldancer
dancer\
\

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-23 Session Authenticity
  • IA-5 Authenticator Management
  • SI-2 Flaw Remediation
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

Directly requires cryptographic-quality, unpredictable session identifiers to protect session authenticity against prediction attacks such as this one.

prevent

Mandates secure generation and management of authenticators (session IDs), explicitly forbidding weak RNGs and predictable values used here.

prevent

Requires timely patching or replacement of the vulnerable Dancer::Session::Abstract component that produces the weak session IDs.

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