Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`.

fedora FEDORA-2026-097fb2e7e9: curl-8.15.0-8.fc43

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-e691fbbfe7 advisory.

    - Fix trailing dot domain super cookie (CVE-2026-8924)
    - Fix SSH improper host validation (CVE-2026-9547)
    - Fix password leak with netrc and user in URL (CVE-2026-8926)
    - Fix cross-origin Digest auth state leak (CVE-2026-11856)
    - Fix cross-proxy Digest auth state leak (CVE-2026-7168)
    - Fix OCSP stapling bypass with Apple SecTrust (CVE-2026-7009)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of libcurl installed on the remote host is 7.10.6 prior to 8.21.0. It is, therefore, affected by a credential disclosure vulnerability:

  - Successfully using libcurl with Digest authentication and then changing the origin to a different host     for a second transfer, reusing the same handle, makes libcurl wrongly pass on the Authorization header     meant for the first host. (CVE-2026-11856)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest**     authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing     the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to     `hostB`. (CVE-2026-11856)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
331599	Fedora 44 : curl (2026-e691fbbfe7)	Nessus	Fedora Local Security Checks	medium
323007	libcurl 7.10.6 < 8.21.0 Cross-Origin Digest Auth State Leak	Nessus	Misc.	critical
322463	Linux Distros Unpatched Vulnerability : CVE-2026-11856	Nessus	Misc.	critical

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