CVE-2026-3256: KTAT HTTP::Session · Generation of Predictable Numbers or Identifiers
Affects KTAT HTTP::SessionSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical : upgrade to 0.54 as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.54
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade HTTP::Session and http-session to 0.54.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| KTATHTTP::Session | Affected
| Fixed in
|
GitHubhttp-sessionpkg:github/http-sessionOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, users should avoid using affected versions and consider implementing alternative secure session ID generation methods that use cryptographically secure random number generators.
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.
References
- metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/SHA1.pm (opens in a new tab)
- metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/MD5.pm (opens in a new tab)
- security.metacpan.org/docs/guides/random-data-for-security.html (opens in a new tab)
- metacpan.org/release/TOKUHIROM/http-session-0.54/changes (opens in a new tab)
- openwall.com/lists/oss-security/2026/03/28/5 (opens in a new tab)