CVE-2026-6276

7.5 HIGH
Published: May 13, 2026 Modified: May 14, 2026
View on NVD

Description

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://curl.se/docs/CVE-2026-6276.html
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
Patch Vendor Advisory
https://curl.se/docs/CVE-2026-6276.json
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
Product
https://hackerone.com/reports/3671818
Source: 2499f714-1537-4658-8207-48ae4bb9eae9
Exploit Issue Tracking Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/29/13
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://hackerone.com/reports/3671818
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Issue Tracking Third Party Advisory

5 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.3%
18th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

haxx