{"id":"CVE-2026-89320","aliases":["EUVD-2026-108654","GHSA-h6w5-722x-2h3m"],"status":"published","title":"HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K(\"\") for all inputs, voiding CBC-HMAC JWE integrity","description":"`HmacShaCryptor.Hash` never hashed its input. For any input it returned `HMAC_K(\"\")` — the MAC of the empty message under the key. Every AES-CBC-HMAC JWE produced or verified by gose therefore carried an authentication tag that is constant per key and independent of the message, removing ciphertext integrity entirely.","severity":{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00174,"percentile":0.06917,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-354"],"published":"2026-10-23T08:56:20Z","modified":"2026-11-04T02:30:49Z","products":[{"vendor":"eclipse foundation","product":"eclipse keypont - gose"}],"references":[{"url":"https://github.com/eclipse-keypont/gose/security/advisories/GHSA-h6w5-722x-2h3m","tags":["exploit","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89320.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89320","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-89320","title":"HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K(\"\") for all inputs, voiding CBC-HMAC JWE integrity","description":"`HmacShaCryptor.Hash` never hashed its input. For any input it returned `HMAC_K(\"\")` — the MAC of the empty message under the key. Every AES-CBC-HMAC JWE produced or verified by gose therefore carried an authentication tag that is constant per key and independent of the message, removing ciphertext integrity entirely.","status":"published","published":"2026-10-23T08:56:20.14Z","modified":"2026-11-02T13:29:45.468Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T18:00:08.034842Z"}],"euvd":[{"id":"EUVD-2026-108654","description":"`HmacShaCryptor.Hash` never hashed its input. For any input it returned `HMAC_K(\"\")` — the MAC of the empty message under the key. Every AES-CBC-HMAC JWE produced or verified by gose therefore carried an authentication tag that is constant per key and independent of the message, removing ciphertext integrity entirely.","status":"published","published":"2026-10-23T08:56:20Z","modified":"2026-11-02T13:29:45Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T16:58:45.261111Z"}],"nvd":[{"id":"CVE-2026-89320","description":"`HmacShaCryptor.Hash` never hashed its input. For any input it returned `HMAC_K(\"\")` — the MAC of the empty message under the key. Every AES-CBC-HMAC JWE produced or verified by gose therefore carried an authentication tag that is constant per key and independent of the message, removing ciphertext integrity entirely.","status":"published","published":"2026-10-23T09:17:08.61Z","modified":"2026-11-02T14:17:40.823Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T20:51:42.579129Z"}],"osv":[{"id":"CVE-2026-89320","title":"HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K(\"\") for all inputs, voiding CBC-HMAC JWE integrity","description":"`HmacShaCryptor.Hash` never hashed its input. For any input it returned `HMAC_K(\"\")` — the MAC of the empty message under the key. Every AES-CBC-HMAC JWE produced or verified by gose therefore carried an authentication tag that is constant per key and independent of the message, removing ciphertext integrity entirely.","status":"published","published":"2026-10-23T08:56:20.14Z","modified":"2026-11-04T02:30:49.508798423Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-354"],"updated_at":"2026-11-04T02:54:44.889498Z"}]}}