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PatchSiren cyber security CVE debrief

CVE-2026-5081 CHORNY CVE debrief

CVE-2026-5081 is a critical vulnerability in Apache::Session::Generate::ModUniqueId, a Perl module used for generating session IDs. The vulnerability arises from the module's use of the UNIQUE_ID environment variable, which is set by the Apache mod_unique_id plugin. This variable is based on the server's IPv4 address, process ID, epoch time, a 16-bit counter, and a thread index, with no obfuscation. As a result, an attacker can potentially guess or obtain the server IP, process IDs, and timestamp, allowing them to predict session IDs.

Vendor
CHORNY
Product
Apache::Session::Generate::ModUniqueId
CVSS
CRITICAL 9.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-06
Original CVE updated
2026-07-15
Advisory published
2026-05-06
Advisory updated
2026-07-15

Who should care

Users of Apache::Session::Generate::ModUniqueId, particularly those in environments where session ID security is crucial.

Technical summary

Apache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 are vulnerable. The module uses the UNIQUE_ID environment variable for session IDs, which can be guessed or obtained by an attacker due to its predictable nature.

Defensive priority

high

Recommended defensive actions

  • Upgrade to a version of Apache::Session::Generate::ModUniqueId that is not vulnerable (e.g., version 1.95 or later).
  • Consider using a different session ID generation module that provides more secure IDs.

Evidence notes

The vulnerability has a CVSS score of 9.1 and is considered critical. It was published on 2026-05-06T13:16:09.833Z and modified on 2026-06-05T20:34:02.643Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-5081 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-5081

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-5081 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-5081

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://httpd.apache.org/docs/current/mod/mod_unique_id.html

    9b29abf9-4ab0-4765-b253-1875cd9b441e - Product

  • Source reference

    Unverified legacy reference

    URL: https://metacpan.org/pod/Apache::Session::Generate::Random

    9b29abf9-4ab0-4765-b253-1875cd9b441e - Product

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.