Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code execution as nobody.
https://www.zerodayinitiative.com/advisories/ZDI-21-157/
https://www.debian.org/security/2022/dsa-5171
https://security.gentoo.org/glsa/202105-14
https://github.com/squid-cache/squid/security/advisories/GHSA-rgf3-9v3p-qp82