CVE-2026-89320
HmacShaCryptor.Hash never hashes its input — returns constant HMAC_K("") for all inputs, voiding CBC-HMAC JWE integrity
What happened?
`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 software and versions
| Software | Version information | Fixed version |
|---|---|---|
| github.com/ThalesGroup/goseEclipse Foundation | affected: 0.9.0 to ≤ 0.13.0-rc1 | See vendor advisory |
| github.com/eclipse-keypont/goseEclipse Foundation | affected: 0 to < 1.0.0-rc1 | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.