CVE-2026-13608

Publication date 2 September 2026

Last updated 10 September 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw in the libcurl SASL negotiation for LDAP authentication allows an incomplete handshake sequence to be misinterpreted as a successful cryptographic verification. An attacker executing a Man-in-the-Middle (MITM) attack can inject a premature or shortcut response that bypasses complete peer validation.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
curl	26.04 LTS resolute	Vulnerable
	24.04 LTS noble	Vulnerable
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Patch details

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

Package	Patch details
curl	Upstream: https://github.com/curl/curl/pull/22213/changes/1a00e2a73675c9521d214aafd6c02b553bfeb022

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.4 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	None

Scores

Parameter	Value
Base score	7.4 · High
Exploitability score	-
Impact score	-

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