Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade curl | Jun 18, 2026 | May 13, 2026 |
| Debian | — | Upgrade curl | Jul 23, 2026 | Jul 23, 2026 |
| Ibm Aix | — | Apply the fix or workaround for curl_advisory12 | Sep 21, 2026 | Sep 21, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Apr 29, 2026 |
| Splunk | — | Upgrade Splunk Enterprise to version 9.4.14Upgrade Splunk Enterprise to version 10.2.6Upgrade Splunk Enterprise to version 10.0.9Upgrade Splunk Enterprise to version 10.4.2 | Aug 20, 2026 | May 13, 2026 |
| Ubuntu | — | Upgrade libcurl4Upgrade libcurl4t64Upgrade libcurl3t64-gnutlsUpgrade libcurl3-gnutlsUpgrade libcurl3-nssUpgrade curl | May 4, 2026 | Apr 29, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | May 13, 2026 |
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