CVE-2026-89320
HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
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.
- Record
CVE-2026-89320- CVSS 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 - Weakness
- CWE-354
- Updated
- 2026-11-02
EUVDEUVD-2026-108654
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.
- Record
EUVD-2026-108654- CVSS 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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-89320- CVSS 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/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 - Weakness
- CWE-354
- Updated
- 2026-11-02
OSV
HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
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.
- Record
CVE-2026-89320- CVSS 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 - Weakness
- CWE-354
- Updated
- 2026-11-04
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-89320 is a high vulnerability (CVSS 8.8) in Eclipse Foundation Keypont - Gose, published October 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.