CVE-2026-4873

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

5.9

Vector

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

Exploitability: 2.2 / Impact: 3.6

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

Description

A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.

Affected (1)

Products: Haxx: Curl

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Haxx Curl	From 7.20.0 to 8.20.0

Related CWEs

Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

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 (4)

https://curl.se/docs/CVE-2026-4873.html

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

PatchVendor Advisory

https://curl.se/docs/CVE-2026-4873.json

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

Vendor Advisory

https://hackerone.com/reports/3621851

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

ExploitIssue TrackingThird Party Advisory

http://www.openwall.com/lists/oss-security/2026/04/29/7

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

Mailing ListPatchThird Party Advisory

Timeline

No history available yet.