{"action":"Upgrade squid to 4.11-1 or later.","affected":[{"fixed":"4.11-1","introduced":"0"}],"component":"squid","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:12","exploited":false,"fixed_versions":["4.11-1"],"id":"tcs_01M5NDRDEVARHFC3ZP4QYY5RC4","modified_at":"2026-09-21T07:01:48.993541433Z","published_at":"2020-04-15T19:15:12.393Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2019-12521","https://security-tracker.debian.org/tracker/CVE-2019-12521"],"severity":{"label":"medium","score":5.9},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2019-12521","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2019-12521"}],"summary":"An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement"}