{"action":"Upgrade bouncycastle to 1.86-1 or later.","affected":[{"fixed":"1.86-1","introduced":"0"}],"component":"bouncycastle","cve_ids":[],"ecosystem":"Debian","ecosystem_qualifier":"Debian:14","exploited":false,"fixed_versions":["1.86-1"],"id":"tcs_01M5NQQQQAATQBFFNF8XV1HT8Y","modified_at":"2026-10-15T10:02:42.329639708Z","published_at":"2026-10-02T08:17:01.310Z","references":["https://osv.dev/vulnerability/DEBIAN-CVE-2026-17507","https://security-tracker.debian.org/tracker/CVE-2026-17507"],"severity":{"label":"high","score":7.5},"sources":[{"source":"osv","source_id":"DEBIAN-CVE-2026-17507#Debian:14/bouncycastle","url":"https://osv.dev/vulnerability/DEBIAN-CVE-2026-17507"}],"summary":"In Bouncy Castle for Java before 1.86, the MLS implementation (org.bouncycastle.mls) holds RFC 9420's uint32 leaf_index in a signed int, so a wire value with the top bit set decodes to a negative numb"}