CVE-2026-89320

8.8 HIGH 0.2% exploit odds Fix listed Crypto

What it is

`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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data tampering.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-11 13:55 UTC ReservedThe CVE id was reserved by its CNA
2026-10-23 09:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-02 14:17 UTC Last updatedMost recent change to the record

Details

Published: 2026-10-23 09:17 UTC
Last modified: 2026-11-02 14:17 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-354
Record status: Deferred

Attack profile CVSS 4.0 · 8.8

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: None
User interaction: None
Confidentiality: Low
Integrity: High
Availability: None

Raw 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

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Fix and advisories

References

NVD record · CVE.org record