CVE-2026-89320

HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity

State: Published
Severity: 8.8 High
Published: Oct 23, 2026
Updated: Oct 23, 2026
Reserved: Sep 11, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	8.8 High	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	eclipse

Weaknesses

CWE-354 Improper Validation of Integrity Check Value

Affected Products

Product	Versions
Eclipse KeyPont - GOSEEclipse Foundation	0.9.0 through 0.13.0-rc1Affected
Eclipse KeyPont - GOSEEclipse Foundation	before 1.0.0-rc1Affected

References

https://github.com/eclipse-keypont/gose/security/advisories/GHSA-h6w5-722x-2h3m

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