Origin validation error in Async-http-client - #VU142432
Published: August 13, 2026
Vulnerability identifier: #VU142432
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-346
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to set arbitrary cookies for a public suffix and influence applications that trust those cookies.
The vulnerability exists due to improper access control in the cookie store domain validation logic when processing Set-Cookie headers with a Domain attribute naming a public suffix. A remote attacker can send a crafted cookie response from a host under the same public suffix to set arbitrary cookies for a public suffix and influence applications that trust those cookies.
Exploitation requires control of a host under the same multi-label public suffix as the victim, such as co.uk, com.au, or github.io.
Affected software
Async-http-client
Remediation
Install security update from vendor's website.
Async-http-client - addressed in versions 2.16.1, 3.0.13