{"action":"Upgrade cbor2 to 5.9.0 or later.","affected":[{"fixed":"5.9.0","introduced":"0"}],"component":"cbor2","cve_ids":["CVE-2026-26209"],"ecosystem":"PyPI","epss":0.00397,"exploited":false,"fixed_versions":["5.9.0"],"ghsa_id":"GHSA-3c37-wwvx-h642","id":"tcs_01M5KGXKQEYQV7K69KPREM9CV9","modified_at":"2026-07-13T07:15:16.978732120Z","published_at":"2026-03-23T19:16:39.530Z","references":["https://osv.dev/vulnerability/PYSEC-2026-2123","https://github.com/agronholm/cbor2/releases/tag/5.9.0","https://github.com/agronholm/cbor2/commit/e61a5f365ba610d5907a0ae1bc72769bba34294b","https://github.com/agronholm/cbor2/pull/275","https://github.com/agronholm/cbor2/security/advisories/GHSA-3c37-wwvx-h642"],"severity":{"label":"high","score":7.5},"sources":[{"source":"osv","source_id":"PYSEC-2026-2123","url":"https://osv.dev/vulnerability/PYSEC-2026-2123"}],"summary":"cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Versions prior to 5.9.0 are vulnerable to a Denial of Service (DoS) attack caused by unco"}