---
cve: "CVE-2026-2439"
severity: "CRITICAL"
cvss: 9.8
epss: "0.5%"
vendor: "BVA"
kev: false
exploited: false
published: "2026-02-16 22:22:41"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-10T16:43:56+01:00"
---

# CVE-2026-2439

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **CPANSec**
- State: PUBLISHED
- Stand: 2026-02-17 14:45:00

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-338** — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
  The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
- **CWE-340** — Generation of Predictable Numbers or Identifiers
  The product uses a scheme that generates numbers or identifiers that are more predictable than required.

## Patch verfügbar (OSV)

- 20bb28e92e8fba307c4ff8264701c215be65e73b (Commit)

## Referenzen

- <https://metacpan.org/release/BVA/Concierge-Sessions-v0.8.4/diff/BVA/Concierge-Sessions-v0.8.5#lib/Concierge/Sessions/Base.pm>
- <https://security.metacpan.org/docs/guides/random-data-for-security.html>
- <https://www.rfc-editor.org/rfc/rfc9562.html#name-security-considerations>
- <https://perldoc.perl.org/5.42.0/functions/rand>
- <https://github.com/bwva/Concierge-Sessions/commit/20bb28e92e8fba307c4ff8264701c215be65e73b>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-2439/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_