---
cve: "CVE-2026-8927"
severity: "CRITICAL"
cvss: 9.1
epss: "44%"
vendor: "curl"
kev: false
exploited: false
published: "2026-07-03 07:16:25"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-11T19:45:08+02:00"
---

# CVE-2026-8927

> 9.1 CRITICAL

## Beschreibung

When reusing a libcurl handle for sequential transfers driven by
environment-variable proxy configuration, libcurl fails to clear the proxy
authentication state between requests. Specifically, if the initial transfer
authenticates against `proxyA` using Digest auth, a subsequent transfer routed
through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended
solely for `proxyA`.

## CVSS-Vektor

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

## Patch verfügbar (OSV)

- 68720b4837284335b2d63cb358f8f6ce65f5bc55 (Commit)

## Referenzen

- <https://curl.se/docs/CVE-2026-8927.json>
- <https://curl.se/docs/CVE-2026-8927.html>
- <https://hackerone.com/reports/3744543>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-8927) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_