---
cve: "CVE-2026-6104"
severity: "MEDIUM"
cvss: 6.3
epss: "47%"
vendor: "PHP Group"
kev: false
exploited: false
published: "2026-05-10 06:16:07"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T06:57:25+02:00"
---

# CVE-2026-6104

> 6.3 MEDIUM · 🧪 PoC

## Beschreibung

In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/RE:M/U:Amber
```

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

## Referenzen

- <https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53>
- <https://access.redhat.com/errata/RHSA-2026:22649>
- <https://access.redhat.com/security/cve/CVE-2026-6104>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2468573>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6104.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-6104) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_