Ubuntu: USN-8227-1 (CVE-2026-5545): curl vulnerabilities

It was discovered that curl incorrectly reused non-TLS connections when
TLS was required in some STARTTLS configurations. A remote attacker could
possibly use this issue to obtain sensitive information. (CVE-2026-4873)

It was discovered that curl incorrectly reused certain HTTP Negotiate
connections. A remote attacker could possibly use this issue to obtain
sensitive information. (CVE-2026-5545)

It was discovered that curl incorrectly reused certain SMB connections. A
remote attacker could possibly use this issue to obtain sensitive
information. (CVE-2026-5773)

It was discovered that curl could leak proxy credentials when handling
redirects in some configurations. A remote attacker could possibly use
this issue to obtain sensitive information. (CVE-2026-6253)

It was discovered that curl could leak cookies because of stale custom
cookie host handling in some requests. A remote attacker could possibly
use this issue to obtain sensitive information. (CVE-2026-6276)

It was discovered that curl could leak .netrc credentials when reusing
proxy connections in some situations. A remote attacker could possibly use
this issue to obtain sensitive information. (CVE-2026-6429)

It was discovered that curl could leak Digest authentication state when
switching proxies in some situations. A remote attacker could possibly use
this issue to obtain sensitive information. (CVE-2026-7168)