Sensitive cookie with improper SameSite attribute in Async-http-client - #VU134579
Published: June 16, 2026
Vulnerability identifier: #VU134579
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-1275
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Asynchttpclient Project
Affected software:
Async-http-client
Async-http-client
Detailed vulnerability description
The vulnerability allows a remote attacker to manipulate cookies for an unrelated domain.
The vulnerability exists due to improper cookie domain validation in ThreadSafeCookieStore when storing cookies from HTTP responses. A remote attacker can cause the client to connect to an attacker-influenced host that sets a crafted cookie to manipulate cookies for an unrelated domain.
Applications are exposed when a single AsyncHttpClient instance shares its cookie store across both attacker-influenced and trusted hosts, such as when following redirects or fetching user-supplied URLs.
Remediation
Install security update from vendor's website.