Http
CVE-2026-3255
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A04:2025 - Cryptographic Failures
ASVS 5.0
V11 - Cryptography Cryptographic PRNG selection
|
| Impact | CVSS 6.5 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to compromise the affected system. |
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Alert meAnalysisAIv1 – Mar 12, 2026
HTTP::Session2 before version 1.12 for Perl generates predictable session identifiers on Windows systems when /dev/urandom is unavailable, falling back to weak randomization using rand() combined with guessable values like PID and epoch time. An attacker could predict valid session IDs to hijack user sessions, as SHA-1 hashing of these weak inputs provides insufficient cryptographic protection. This affects Perl applications using HTTP::Session2 on Windows platforms where secure random sources are not accessible.
Earlier versions of this analysis (1)
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. [CVSS 6.5 MEDIUM]
RemediationAI
A vendor patch is available — apply it immediately. Restrict network access to the affected service where possible.
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Technical ContextAI · show details
Affects the rand component of Http\. 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 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 /d
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
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 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.
Executive ViewAI
CVE-2026-3255 presents notable security risk rated CVSS 6.5. Exploitation could compromise the security of affected deployments. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
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SSVC AssessmentENISA
Priority Score
Affected Products (CPE)CVE.org
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