---
cve: "CVE-2026-23478"
severity: "CRITICAL"
cvss: 10.0
epss: "41%"
vendor: "calcom"
kev: false
exploited: false
published: "2026-01-13 22:16:08"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T11:03:11+02:00"
---

# CVE-2026-23478

> 10.0 CRITICAL · 🧪 PoC

## Beschreibung

Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 0099c72f53957a1b65163f8176eeb718ad3664f8 (Commit)

## Referenzen

- <https://github.com/calcom/cal.com/security/advisories/GHSA-7hg4-x4pr-3hrg>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-23478) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_