CVE-2026-3256: CWE-340 Generation of Predictable Numbers or Identifiers in KTAT HTTP::Session
HTTP::Session versions through 0.53 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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. The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.
AI Analysis
Technical Summary
HTTP::Session versions up to 0.53 use HTTP::Session::ID::SHA1 by default to generate session IDs. This method seeds a SHA-1 hash with the built-in rand function, high resolution epoch time, and the process ID (PID). The PID is drawn from a small set of values, and the epoch time can be guessed or leaked, making the session IDs predictable. The built-in rand function is not cryptographically secure, further weakening the randomness of session IDs. Additionally, HTTP::Session::ID::MD5, which uses MD5 hashing, suffers from the same flaw. This predictable session ID generation can allow attackers to hijack sessions or impersonate users.
Potential Impact
The vulnerability allows attackers to predict or guess session identifiers due to weak randomness and predictable inputs. This compromises session confidentiality and integrity, potentially enabling session hijacking or unauthorized access. The CVSS score of 9.8 reflects critical impact on confidentiality, integrity, and availability of affected systems using HTTP::Session for session management.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users of HTTP::Session should avoid using the default session ID generators that rely on insecure randomness. It is recommended to implement a cryptographically secure random number generator for session ID creation or use alternative session management libraries that provide secure session ID generation. Monitor vendor advisories for any future updates or official fixes.
CVE-2026-3256: CWE-340 Generation of Predictable Numbers or Identifiers in KTAT HTTP::Session
Description
HTTP::Session versions through 0.53 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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. The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
HTTP::Session versions up to 0.53 use HTTP::Session::ID::SHA1 by default to generate session IDs. This method seeds a SHA-1 hash with the built-in rand function, high resolution epoch time, and the process ID (PID). The PID is drawn from a small set of values, and the epoch time can be guessed or leaked, making the session IDs predictable. The built-in rand function is not cryptographically secure, further weakening the randomness of session IDs. Additionally, HTTP::Session::ID::MD5, which uses MD5 hashing, suffers from the same flaw. This predictable session ID generation can allow attackers to hijack sessions or impersonate users.
Potential Impact
The vulnerability allows attackers to predict or guess session identifiers due to weak randomness and predictable inputs. This compromises session confidentiality and integrity, potentially enabling session hijacking or unauthorized access. The CVSS score of 9.8 reflects critical impact on confidentiality, integrity, and availability of affected systems using HTTP::Session for session management.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users of HTTP::Session should avoid using the default session ID generators that rely on insecure randomness. It is recommended to implement a cryptographically secure random number generator for session ID creation or use alternative session management libraries that provide secure session ID generation. Monitor vendor advisories for any future updates or official fixes.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- CPANSec
- Date Reserved
- 2026-02-26T11:59:23.755Z
- Cvss Version
- null
- State
- PUBLISHED
Threat ID: 69c826972b68dbd88eafb4bf
Added to database: 3/28/2026, 7:05:59 PM
Last enriched: 4/5/2026, 10:37:02 AM
Last updated: 5/12/2026, 12:50:18 PM
Views: 75
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