CyberSecBulletin
CVE-2026-5087NVD status: Analyzed

PAGI::Middleware::Session::Store::Cookie: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Published Updated By the CyberSecBulletin desk

CVE-2026-5087 is a high-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in PAGI::Middleware::Session::Store::Cookie from Jjnapiork, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected PAGI::Middleware::Session::Store::Cookie versions: 0.001003 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of PAGI::Middleware::Session::Store::Cookie you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
JJNAPIORKPAGI::Middleware::Session::Store::Cookie0.001003 and earlierNot stated
JjnapiorkPagi0.001003 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CISA (ADP).

Official description

PAGI::Middleware::Session::Store::Cookie versions through 0.001003 for Perl generates random bytes insecurely. PAGI::Middleware::Session::Store::Cookie attempts to read bytes from the /dev/urandom device directly. If that fails (for example, on systems without the device, such as Windows), then it will emit a warning that recommends the user install Crypt::URandom, and then return a string of random bytes generated by the built-in rand function, which is unsuitable for cryptographic applications. This modules does not use the Crypt::URandom module, and installing it will not fix the problem. The random bytes are used for generating an initialisation vector (IV) to encrypt the cookie. A predictable IV may make it easier for malicious users to decrypt and tamper with the session data that is stored in the cookie.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.

How developers prevent this class of flaw

  • Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.

More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities

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