---
cve: "CVE-2026-110354"
severity: "HIGH"
cvss: 7.5
epss: "0.8%"
vendor: "HAProxy"
kev: false
exploited: false
published: "2026-10-22 03:16:31"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-11-05T19:10:00+01:00"
---

# CVE-2026-110354

> 7.5 HIGH

## Beschreibung

HAProxy 3 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (persistent worker-thread CPU exhaustion) via an HTTP/1.1 chunked request. Although the H1 multiplexer drains the request before closing the stream, the parser repeatedly re-processes the same bytes without making progress. The affected thread stays busy at 100% CPU after timeouts expire and after the client disconnects, and repeated requests can consume all worker threads until the process is restarted.

## CNA-Record (Kanon, cvelistV5)

- CNA: **mitre**
- State: PUBLISHED
- Stand: 2026-10-22 19:10:34
- CNA-CVSS: **7.5** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

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

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-835** — Loop with Unreachable Exit Condition
  The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

## Patch verfügbar (OSV)

- fcfabd0d909afaf379a4e30eb43c5229ddbb9d70
- 37f3ad8aa35bb34b2363b73541780df6c7226270

## BSI-Hinweise (deutsch)

- [HAProxy: Mehrere Schwachstellen ermöglichen Denial of Service](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-4114) — _BSI-Einstufung: mittel_
  Ein Angreifer kann mehrere Schwachstellen in HAProxy ausnutzen, um einen Denial of Service Angriff durchzuführen.

## Referenzen

- <https://git.haproxy.org/?p=haproxy.git;a=commit;h=077906da140a35873bf451d7e9f67646c9f37c81>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-110354/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_