Vulnerability · Published Oct 23, 2026 · Assigned by eclipse
CVE-2026-89320HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
High 8.8
In plain English
A high-severity security flaw in Eclipse KeyPont - GOSE from Eclipse Foundation. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).
Severity (CVSS 4.0)8.8High
Exploit odds (30 days)0.2%top 93.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Eclipse Foundation | Eclipse KeyPont - GOSE | 0.9.0 – through 0.13.0-rc1 |
| Eclipse Foundation | Eclipse KeyPont - GOSE | 0 – before 1.0.0-rc1 |
Weakness: CWE-354 · 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