---
cve: "CVE-2026-91939"
severity: "CRITICAL"
cvss: 9.3
epss: "1%"
vendor: "Cotonti"
kev: false
exploited: false
published: "2026-09-15 21:16:48"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-10T17:44:17+02:00"
---

# CVE-2026-91939

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://github.com/Cotonti/Cotonti/issues/1888>
- <https://github.com/Cotonti/Cotonti/pull/1889>
- <https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php>
- <https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php>
- <https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php>
- <https://github.com/Cotonti/Cotonti>
- <https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-91939/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_