CVE-2026-4873

Publication date 29 April 2026

Last updated 29 April 2026


Ubuntu priority

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 will bypass the TLS requirement and instead transmit data unencrypted.

Read the notes from the security team

Why is this CVE low priority?

This flaw requires a rather special series of events to trigger. Such a series is unlikely to be used much in the wild.

Learn more about Ubuntu priority

Status

Package Ubuntu Release Status
curl 26.04 LTS resolute
Needs evaluation
25.10 questing
Vulnerable
24.04 LTS noble
Vulnerable
22.04 LTS jammy
Vulnerable
20.04 LTS focal
Vulnerable
18.04 LTS bionic
Vulnerable
16.04 LTS xenial
Vulnerable
14.04 LTS trusty
Vulnerable

Notes


ebarretto

Introduced-in: https://github.com/curl/curl/commit/ec3bb8f727405642a

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
curl

Access our resources on patching vulnerabilities