CVE-2026-6276

HIGH EPSS 20.7%
Published May 13, 20261mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published May 13, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
20.7% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-319

Affected Products 1

VendorProductVersionRange
haxxcurl*≥7.71.0  –  <8.20.0

References 4

  • openwall.com http://www.openwall.com/lists/oss-security/2026/04/29/13
    Mailing ListThird Party Advisory
  • curl.se https://curl.se/docs/CVE-2026-6276.html
    PatchVendor Advisory
  • curl.se https://curl.se/docs/CVE-2026-6276.json
    Product
  • hackerone.com https://hackerone.com/reports/3671818
    ExploitIssue TrackingThird Party Advisory

Remediation

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