Privilege Esc Escalation: libcurl Fails to Clear Proxy Auth Credentials
CVE-2026-9079 Published on July 3, 2026

stale proxy password leak
libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for subsequent transfers that should not know nor use them.

NVD

Vulnerability Analysis

CVE-2026-9079 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Insufficiently Protected Credentials

The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.


Products Associated with CVE-2026-9079

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-9079 are published in these products:

Canonical Ubuntu Linux
 
Haxx Curl
 
Red Hat Http Server
 

Affected Versions

curl: curl: curl: