Description
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`.
References
https://curl.se/docs/CVE-2026-11856.html
PatchVendor Advisory
https://curl.se/docs/CVE-2026-11856.json
Vendor Advisory
https://hackerone.com/reports/3793260
ExploitIssue TrackingThird Party Advisory
https://hackerone.com/reports/3793260
ExploitIssue TrackingThird Party Advisory
CVSS impact metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8 · Critical
Information
Source identifier
2499f714-1537-4658-8207-48ae4bb9eae9
Vulnerability status
Modified
Published
2026-07-03T07:16:23.973Z
3 months agoLast modified
2026-09-15T07:16:25.870Z
3 weeks ago