---
cve: "CVE-2026-9546"
severity: "HIGH"
cvss: 7.5
epss: "0.5%"
vendor: "curl"
kev: false
exploited: false
published: "2026-07-03 07:16:25"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T00:02:38+02:00"
---

# CVE-2026-9546

> 7.5 HIGH

## Beschreibung

A vulnerability in libcurl caused the HTTP `Referer:` header to persist even
when explicitly cleared. While the documentation states that passing NULL to
`CURLOPT_REFERER` suppresses the header, the option failed to clear the
internal state. As a result, the previous referrer string was erroneously
reused and sent in subsequent requests, potentially leaking sensitive
information to unintended servers.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
```

| 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 | Keine | good |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 68720b4837284335b2d63cb358f8f6ce65f5bc55 (Commit)

## Referenzen

- <https://curl.se/docs/CVE-2026-9546.json>
- <https://curl.se/docs/CVE-2026-9546.html>
- <https://hackerone.com/reports/3754343>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-9546) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_