`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.
History

Mon, 02 Nov 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 26 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
First Time appeared Eclipse
Eclipse keypont-gose
Vendors & Products Eclipse
Eclipse keypont-gose

Fri, 23 Oct 2026 09:15:00 +0000

Type Values Removed Values Added
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.
Title HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
Weaknesses CWE-354
References
Metrics cvssV4_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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: eclipse

Published: 2026-10-23T08:56:20.140Z

Updated: 2026-11-02T13:29:45.468Z

Reserved: 2026-09-11T13:55:59.296Z

Link: CVE-2026-89320

cve-icon Vulnrichment

Updated: 2026-11-02T13:29:22.903Z

cve-icon NVD

Status : Deferred

Published: 2026-10-23T09:17:08.610

Modified: 2026-11-02T14:17:40.823

Link: CVE-2026-89320

cve-icon Redhat

No data.