CVE-2026-84185
A flaw was found in the jwcrypto library, which is used for implementing Javascript Object Signing and Encryption (JOSE) standards. The issue occurs when the library verifies a General JSON Serialization JWS using a set of keys. Due to a coding error, the library fails to correctly identify the specific key ID (kid) and may instead accept a signature made by any valid key in the set. This can allow an attacker with a valid key to bypass authorization checks in applications that rely on the key ID to identify specific tenants or users.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a less than 0.1% chance of attack attempts being seen in the next 30 days, ranking above 0% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Fastnexa security experts
Not sure if your company is exposed to CVE-2026-84185?
Tell us where you run the affected software and a Fastnexa penetration tester will check whether this flaw, or others like it, can be used against your websites, apps and network.
The full test is free for our first 10 founding clients until 31 December 2026. See the offer
Think you’ve already been hit? Don’t wait on a form: call or WhatsApp +1 (732) 454 2616. We reply within 1 hour, 24/7. Emergency help →
Scoring
- CVSS
- 5.9 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N- Weakness
- CWE-347
- Assigned by
- secalert@redhat.com
Dates
- Published
- 2026-09-03
- Last modified
- 2026-09-08
- Sources
- NVD