Squid before 4.4 has XSS via a crafted X.509 certificate during HTTP(S) error page generation for certificate errors.
https://github.com/squid-cache/squid/pull/306
http://www.squid-cache.org/Versions/v5/changesets/squid-5-6feeb15ff312f3e145763adf8d234ed6a0b3f11d.patch
http://www.squid-cache.org/Advisories/SQUID-2018_4.txt
Source: Mitre, NVD
Published: 2018-11-09
Updated: 2018-12-11
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N