CVE-2026-33515: squid-cache squid Out-of-bounds Read

Vulnerability summary

CVE-2026-33515 is a medium (CVSS 6.9) Out-of-bounds Read vulnerability in squid-cache squid. EPSS estimates a 1.04% chance of exploitation in the next 30 days, higher than 63.4% of scored vulnerabilities.

Timeline

1. 26-03-2026
   PublishedVulnerability first disclosed.
2. 26-03-2026
   Last modifiedVulnerability information updated.

Description

Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing sensitive information when responding with errors to invalid ICP requests. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero `icp_port`). This problem cannot be mitigated by denying ICP queries using `icp_access` rules. Version 7.5 contains a patch.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
• CWE-1289Improper Validation of Unsafe Equivalence in InputThe product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.