Vulnerability DatabaseCVE-2026-11856
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CVE-2026-11856
Published:July 03, 2026
Updated:July 21, 2026
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 Packages
https://github.com/curl/curl.git (GITHUB):
Affected version(s) >=curl-7_10_6 <curl-8_21_0
Fix Suggestion:
Update to version curl-8_21_0
Additional Notes
The description of this vulnerability differs from MITRE.
Related Resources (3)
https://hackerone.com/reports/3793260
https://curl.se/docs/CVE-2026-11856.html
https://curl.se/docs/CVE-2026-11856.json
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CVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Authentication Bypass by Capture-replay
CWE-294
EPSS
Base Score:
1.06