CPANSA-Apache-Session-2026-5081: Apache-Session vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-05-06T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-05-06T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 9.1 | Severity | |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
Apache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 for Perl session ids are insecure. Apache::Session::Generate::ModUniqueId (added in version 1.54) uses the value of the UNIQUE_ID environment variable for the session id. The UNIQUE_ID variable is set by the Apache mod_unique_id plugin, which generates unique ids for the request. The id is based on the IPv4 address, the process id, the epoch time, a 16-bit counter and a thread index, with no obfuscation. The server IP is often available to the public, and if not available, can be guessed from previous session ids being issued. The process ids may also be guessed from previous session ids. The timestamp is easily guessed (and leaked in the HTTP Date response header). The purpose of mod_unique_id is to assign a unique id to requests so that events can be correlated in different logs. The id is not designed, nor is it suitable for security purposes.
Vulnerabilities
CVE-2026-5081
Vulnerability DescriptionApache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 for Perl session ids are insecure.
Apache::Session::Generate::ModUniqueId (added in version 1.54) uses the value of the UNIQUE_ID environment variable for the session id. The UNIQUE_ID variable is set by the Apache mod_unique_id plugin, which generates unique ids for the request. The id is based on the IPv4 address, the process id, the epoch time, a 16-bit counter and a thread index, with no obfuscation.
The server IP is often available to the public, and if not available, can be guessed from previous session ids being issued. The process ids may also be guessed from previous session ids. The timestamp is easily guessed (and leaked in the HTTP Date response header).
The purpose of mod_unique_id is to assign a unique id to requests so that events can be correlated in different logs. The id is not designed, nor is it suitable for security purposes.
| Weakness | CWE-340 : Generation of Predictable Numbers or Identifiers |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Apache-Session greater than or equal 1.54 |
|
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Apache-Session-2026-5081 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-apache-session-2026-5081.json - https://httpd.apache.org/docs/current/mod/mod_unique_id.html external
https://httpd.apache.org/docs/current/mod/mod_unique_id.html - https://metacpan.org/pod/Apache::Session::Generate::Random external
https://metacpan.org/pod/Apache::Session::Generate::Random - http://www.openwall.com/lists/oss-security/2026/05/06/6 external
http://www.openwall.com/lists/oss-security/2026/05/06/6 - CVE-2026-5081 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-5081
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Wed May 6 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/