CVE-2026-5081 Apache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 for Perl session ids are insecure
Insecure session ID generation in Apache::Session::Generate::ModUniqueId allows attackers to predict session IDs and hijack user sessions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5081?
CVE-2026-5081 is a critical vulnerability in CHORNY Apache::Session::Generate::ModUniqueId, published on 6 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-5081?
It affects 1 product.
Products include Chorny Apache\.
How do I fix CVE-2026-5081?
No fix has been published for CVE-2026-5081 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-5081 being exploited?
There is no known exploitation of CVE-2026-5081 in the wild and no public exploit code.
Other vulnerabilities in CHORNY Apache::Session::Generate::ModUniqueId
Sources
Also known as DEBIAN-CVE-2026-5081, GHSA-546v-xqjf-qgcr, UBUNTU-CVE-2026-5081.