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.
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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| curl | curl | unaffected |
|
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Project Subscriptions
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 03 Jul 2026 06:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | sending old referer | |
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: curl
Published:
Updated: 2026-07-03T06:18:14.447Z
Reserved: 2026-05-26T06:45:18.723Z
Link: CVE-2026-9546
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.