CVE-2025-62168
CriticalCVSS 10.0Exploitation Probability (EPSS)
Very high risk99th percentile - higher than 99% of all known CVEs
Summary
In Squid versions prior to 7.2, a failure to redact HTTP authentication credentials in error handling allows information disclosure. A script can bypass browser security protections and learn the credentials a trusted client uses to authenticate, potentially allowing a remote client to identify security tokens or credentials used internally by a web application using Squid for backend load balancing. The vulnerability does not require Squid to be configured with HTTP authentication and is fixed in version 7.2.
Risk Assessment
Potential disclosure of internal tokens or credentials of a web application, which may enable unauthorized access to protected resources. The risk affects organizations using Squid as a proxy or load balancer for applications with authentication.
Recommendation
Update Squid to version 7.2 or later. As a workaround, disable debug information in administrator mailto links by setting email_err_data off in squid.conf.
Other vulnerabilities in Squid
See all- CVE-2016-4556High
A double free vulnerability in Esi.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via a crafted Edge Side Includes (ESI) response.
- CVE-2016-4554High
The mime_header.cc file in Squid before version 3.5.18 contains a vulnerability that allows remote attackers to bypass intended same-origin restrictions and potentially conduct cache-poisoning attacks via a crafted HTTP Host header, known as a 'header smuggling' issue.
- CVE-2016-4553High
The client_side.cc file in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when an absolute URI is provided, allowing remote attackers to conduct cache-poisoning attacks.
- CVE-2016-4054High
A buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.
- CVE-2016-4052High
Multiple stack-based buffer overflows in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allow remote HTTP servers to cause a denial of service or execute arbitrary code via crafted Edge Side Includes (ESI) responses.
- CVE-2016-3948High
Squid versions 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, allowing remote attackers to cause a denial of service via a crafted HTTP response related to Vary headers.
- CVE-2016-2571High
In Squid 3.x before version 3.5.15 and 4.x before version 4.0.7, http.cc continues to store data after a response-parsing failure. This allows remote HTTP servers to cause a denial of service by sending a malformed response.
- CVE-2016-2569High
Squid versions 3.x before 3.5.15 and 4.x before 4.0.7 do not properly append data to String objects, allowing remote servers to cause a denial of service (assertion failure and daemon exit) via a long string, as demonstrated by a crafted HTTP Vary header.
- CVE-2026-61642High
Squid is a caching proxy for the Web. From 3.3.0.1 to before 7.6, due to improper enforcement of behavioral workflow, Squid is vulnerable to a Request Smuggling attack against HTTP/1.1 Transfer-Encoding, accepting the prohibited 'Transfer-Encoding: identity' form.
- CVE-2026-33526High
Squid versions prior to 7.5 contain a heap Use-After-Free vulnerability in ICP traffic handling, allowing a remote attacker to perform a reliable and repeatable Denial of Service attack. The attack requires ICP support enabled (non-zero `icp_port`) and cannot be mitigated by `icp_access` rules.
Original NVD description (English source)
Squid is a caching proxy for the Web. In Squid versions prior to 7.2, a failure to redact HTTP authentication credentials in error handling allows information disclosure. The vulnerability allows a script to bypass browser security protections and learn the credentials a trusted client uses to authenticate. This potentially allows a remote client to identify security tokens or credentials used internally by a web application using Squid for backend load balancing. These attacks do not require Squid to be configured with HTTP authentication. The vulnerability is fixed in version 7.2. As a workaround, disable debug information in administrator mailto links generated by Squid by configuring squid.conf with email_err_data off.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS