Stack-based buffer overflow in Squid - #VU149501
Published: September 14, 2026
Vulnerability identifier: #VU149501
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-121
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to modify data or cause a denial of service.
The vulnerability exists due to a stack-based buffer overflow in ICAP authentication when processing user= and password= credential annotations for an ICAP service. A local privileged user can pass excessively long credentials through these annotations to modify data or cause a denial of service.
Exploitation requires Squid to be configured to use an ICAP server in conjunction with a misbehaving external ACL authentication helper.
Affected software
Squid
Remediation
Install security update from vendor's website.
Squid - update to 7.7