CVE-2026-9546
7.5
HIGH
CVSS 3.1
EPSS 0.65%
Description
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.
How to fix CVE-2026-9546
To remediate CVE-2026-9546, upgrade the affected package to a fixed version below.
- —upgrade to 8.21.0-r0 or later
Is CVE-2026-9546 being exploited?
Low — EPSS is 0.7%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 8.18.0, < 8.21.0-r0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |