What is CVE-2026-2439?

Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id function in Concierge::Sessions::Base defaults to using the uuidgen command to generate a UUID, with a fallback to using Perl's built-in rand function. Neither of these methods are secure, and attackers are able to guess session_ids that can grant them access to systems. Specifically, * There is no warning when uuidgen fails. The software can be quietly using the fallback rand() function with no warnings if the command fails for any reason. * The uuidgen command will generate a time-based UUID if the system does not have a high-quality random number source, because the call does not explicitly specify the --random option. Note that the system time is shared in HTTP responses. * UUIDs are identifiers whose mere possession grants access, as per RFC 9562. * The output of the built-in rand() function is predictable and unsuitable for security applications.

What is the severity of CVE-2026-2439?

CVE-2026-2439 has a CVSS v3 score of 0, which is classified as Low severity.

Is there an exploit available for CVE-2026-2439?

No known public exploits are currently available for CVE-2026-2439.

Is there a patch available for CVE-2026-2439?

Yes, patches are available for CVE-2026-2439. Check the vendor advisories for update instructions.

CVE-2026-2439 - CVE Details, Severity, and Analysis

Severity Scores

CVSS v30.0

CVSS v20.0

Priority Score0.0

EPSS Score0.0

None

Exploitation LikelihoodMinimal

0.00%EPSS

Very low probability of exploitation

Monitor and patch as resources allow

0.00%

EPSS

0.0

CVSS

No

Exploit

Yes

Patch

Low Priority

no major risk factors

EPSS predicts the probability of exploitation in the next 30 days based on real-world threat data, complementing CVSS severity scores with actual risk assessment.

Description

Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id function in Concierge::Sessions::Base defaults to using the uuidgen command to generate a UUID, with a fallback to using Perl's built-in rand function. Neither of these methods are secure, and attackers are able to guess session_ids that can grant them access to systems. Specifically,

There is no warning when uuidgen fails. The software can be quietly using the fallback rand() function with no warnings if the command fails for any reason.
The uuidgen command will generate a time-based UUID if the system does not have a high-quality random number source, because the call does not explicitly specify the --random option. Note that the system time is shared in HTTP responses.
UUIDs are identifiers whose mere possession grants access, as per RFC 9562.
The output of the built-in rand() function is predictable and unsuitable for security applications.

CVSS v3 Breakdown

Attack Vector:-

Attack Complexity:-

Privileges Required:-

User Interaction:-

Scope:-

Confidentiality:-

Integrity:-

Availability:-

Patch References

Github.com