Cyber Resilience

CVE-2026-3255

Tokuhirom Http\ \

Published
27 February 2026
Modified
04 March 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS Score 0.0042 34th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-3255 is a medium-severity PRNG (CWE-338) vulnerability in Tokuhirom Http\. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 34th 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)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function. The HTTP::Session2 session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID…

more

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. HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.

CWE(s)
CWE-338CWE-340

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.
attack.mitre.org →
Why these techniques?

Weak predictable session ID generation enables remote attackers to guess/forge valid sessions against the public-facing Perl web application.

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

CVEs Like This One

CVE-2026-5082Same vendor: Tokuhirom
CVE-2025-15604Same vendor: Tokuhirom
CVE-2026-3257Same vendor: Tokuhirom
CVE-2026-5080Shared CWE-338, CWE-340
CVE-2025-40920Shared 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-2026-2439Shared CWE-338, CWE-340
CVE-2024-40762Shared CWE-338

Affected Assets

tokuhirom
http\
\

Mitigating Controls

Control response

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

SC-23 Session Authenticity good match
prevent

Directly requires session identifiers to be unpredictable and resistant to guessing or capture, countering the weak rand()/PID/time seeding in HTTP::Session2.

IA-5 Authenticator Management good match
prevent

Mandates management of authenticators (including session tokens) to ensure sufficient randomness and strength, blocking the fallback to non-cryptographic PRNG described in the CVE.

SC-13 Cryptographic Protection partial match
prevent

Requires cryptographic mechanisms for protecting sensitive data such as session identifiers, addressing the use of SHA-1 seeded with insecure rand().

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.

A.8.24 Use of cryptography mostly match
prevents

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

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

Security testing can detect use of weak random number generators.

A.8.25 Secure development life cycle partial match
prevents

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

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify cryptographically strong random number generation.

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

Secure engineering principles include selection of appropriate cryptographic primitives.

A.8.28 Secure coding partial match
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