CVE-2026-3256CRITICAL 9.8EPSS p40.6%
CVE-2026-3256CVE-2026-3256
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.
Scoring
| CVSS 3.1 | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.53% probability of exploitation · percentile 40.6% · 2026-06-18T12:00:27Z |
| Published | 2026-03-28 |
| Last modified | 2026-04-01 |
Underlying weaknesses· 2
References
2
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)cwe-338 | 0% | live |
| Weakness | Generation of Predictable Numbers or Identifierscwe-340 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.