CVE-2026-9546
sending old referer
- State
- Published
- Severity
- 7.5 High
- Published
- Jul 3, 2026
- Updated
- Sep 15, 2026
- Reserved
- May 26, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | CISA-ADP |
Weaknesses
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
Affected Products
| Product | Versions |
|---|---|
curlcurl |
|
curlcurl |
|
curlcurl |
|
References
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