CVE-2026-11856
CriticalCVSS 9.8Exploitation Probability (EPSS)
Elevated risk51th percentile - higher than 51% of all known CVEs
Summary
A vulnerability in libcurl causes the Authorization header intended for the original host to be incorrectly forwarded to a different host when reusing a handle for HTTP transfers with Digest authentication.
Risk Assessment
The organization risks leaking authentication credentials to an unauthorized server, potentially leading to unauthorized access to resources.
Recommendation
It is recommended to immediately update libcurl to a patched version and avoid reusing handles between different hosts with Digest authentication.
Original NVD description (English source)
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`.