---
cve: "CVE-2026-45185"
severity: "CRITICAL"
cvss: 9.8
epss: "1.2%"
vendor: "exim"
kev: false
exploited: false
published: "2026-05-12 20:16:46"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T06:39:46+02:00"
---

# CVE-2026-45185

> 9.8 CRITICAL

## Beschreibung

Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.

## 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 |

## Referenzen

- <https://exim.org>
- <https://code.exim.org/exim/wiki/wiki/EximSecurity>
- <https://exim.org/static/doc/security/CVE-2026-45185.txt>
- <https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim>
- <https://news.ycombinator.com/item?id=48111748>
- <https://www.openwall.com/lists/oss-security/2026/05/12/4>
- <https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/>
- <http://www.openwall.com/lists/oss-security/2026/05/12/25>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-45185) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_