Cleartext transmission of sensitive information in Async-http-client - #VU142450
Published: August 13, 2026
Vulnerability identifier: #VU142450
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-319
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to cleartext transmission of sensitive information in SOCKS proxy authentication handling when sending requests through a SOCKS proxy over plaintext HTTP. A remote attacker can operate a hostile origin server or observe traffic on the origin side of the connection to obtain proxy credentials and disclose sensitive information.
Without preemptive proxy authentication, a hostile origin can reply with a 407 challenge and cause the client to send the proxy credentials over the same tunnel. Connection-oriented authentication schemes including NTLM, Kerberos, and SPNEGO are affected.
Affected software
Async-http-client
Remediation
Install security update from vendor's website.
Async-http-client - addressed in versions 2.16.1, 3.0.12