{"action":"Upgrade firefox-esr to 91.3.0esr-1 or later.","affected":[{"fixed":"91.3.0esr-1","introduced":"0"}],"component":"firefox-esr","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:13","exploited":false,"fixed_versions":["91.3.0esr-1"],"id":"tcs_01M5NFX4E92GJBGWJ41AMY67KP","modified_at":"2026-10-23T18:03:46.021365169Z","published_at":"2021-12-08T22:15:08.947Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2021-38507","https://security-tracker.debian.org/tracker/CVE-2021-38507"],"severity":{"label":"medium","score":6.5},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2021-38507#Debian:13/firefox-esr","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2021-38507"}],"summary":"The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origi"}