CVE-2026-4873

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.

Score

CVSS 3.1 5.9 Medium

Status

Modified - 2499f714-1537-4658-8207-48ae4bb9eae9

Published

2026-05-13

Last modified

2026-09-15

Weaknesses

CWE-295, CWE-319

Affected products

• Curl (Curl)
• Curl (Haxx)

References

• https://curl.se/docs/CVE-2026-4873.html
• https://curl.se/docs/CVE-2026-4873.json
• https://hackerone.com/reports/3621851
• http://www.openwall.com/lists/oss-security/2026/04/29/7