CVE & CISA-KEV Catalog

CVE-2026-3256

CRITICAL
9.8
CVSS v3
NVD

Description

HTTP::Session versions before 0.54 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.

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

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CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.53%probability of exploitation in 30 days
41stpercentile

Moderate risk: more likely to be exploited than 41% of all known CVEs.

References

Other references1

Related Vulnerabilities

Other CWE-338 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2008-0166High7.571%-Fix
CVE-2009-2367Critical9.823%--
CVE-2024-29868Critical9.16.0%--
CVE-2024-31497Medium5.95.8%-Fix
CVE-2021-43799High8.65.4%-Fix
CVE-2008-3280Medium5.94.0%--
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-29.