CVE-2026-9546 Affecting curl package, versions <8.21.0-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.21% (11th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ALPINE324-CURL-17717618
  • published30 Jun 2026
  • disclosed3 Jul 2026

Introduced: 30 Jun 2026

NewCVE-2026-9546  (opens in a new tab)

How to fix?

Upgrade Alpine:3.24 curl to version 8.21.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream curl package and not the curl package as distributed by Alpine. See How to fix? for Alpine:3.24 relevant fixed versions and status.

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.