CVE-2026-11856

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`.

Affected products

Ibm Aix, Ubuntu, Libcurl

Haxx Curl

< 8.21.0

CVSS 3.1

9.8 CRITICAL

EPSS

0.6% (46th percentile)

Weakness

CWE-294

NVD status

Analyzed

Published

2026-07-03

No exploit for CVE-2026-11856 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.