CVE-2026-2439: Bva Concierge::sessions vulnerability (CVSS 9.8)

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 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Bva Concierge::sessions≥ 0.8.1 < 0.8.5

Remediation

Fixed in

Bva Concierge::sessions≥ 0.8.5

Patch & vendor advisories

https://github.com/bwva/Concierge-Sessions/commit/20bb28e92e8fba307c4ff8264701c215be65e73b

References

https://github.com/bwva/Concierge-Sessions/commit/20bb28e92e8fba307c4ff8264701c215be65e73bPatch
https://metacpan.org/release/BVA/Concierge-Sessions-v0.8.4/diff/BVA/Concierge-Sessions-v0.8.5#lib/Concierge/Sessions/Base.pmProductRelease Notes
https://perldoc.perl.org/5.42.0/functions/randThird Party Advisory
https://security.metacpan.org/docs/guides/random-data-for-security.htmlThird Party Advisory
https://www.rfc-editor.org/rfc/rfc9562.html#name-security-considerationsThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-2439 being actively exploited?

CVE-2026-2439 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.43%.

How severe is CVE-2026-2439?

CVE-2026-2439 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.43% probability of exploitation.

Which products are affected by CVE-2026-2439?

Affected products include Bva Concierge::sessions.

How do I fix CVE-2026-2439?

Upgrade affected software to a fixed version, for example Bva Concierge::sessions 0.8.5 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-2439 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo