CVE-2026-6276

Published: May 13, 2026Modified: Jun 17, 2026

7.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitability: 3.9 / Impact: 3.6

Source: 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.

Affected (1)

Products: Haxx: Curl

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Haxx Curl	From 7.71.0 to 8.20.0

Related CWEs

Cleartext Transmission of Sensitive Information

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

References (5)

https://curl.se/docs/CVE-2026-6276.html

Source: 2499f714-1537-4658-8207-48ae4bb9eae9

PatchVendor 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

ExploitIssue TrackingThird Party Advisory

http://www.openwall.com/lists/oss-security/2026/04/29/13

Source: af854a3a-2127-422b-91ae-364da2661108

Mailing ListThird Party Advisory

https://hackerone.com/reports/3671818

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

ExploitIssue TrackingThird Party Advisory

Timeline

No history available yet.