CVE-2026-65628
Infinite recursion (CPU denial-of-service) in JOSE.JWK.shared_secret/2 on mismatched key types
What happened?
jose_jwk:shared_secret/2 (exposed in Elixir as JOSE.JWK.shared_secret/2) derives an ECDH shared secret from two JWKs. Its first function clause only matches when both JWKs carry the same key type (kty) module, and its fallback clause re-invokes itself as shared_secret(from(YourJWK), from(MyJWK)). Because from/1 returns an already-parsed jose_jwk record unchanged, passing two JWKs whose key types differ (for example an EC key and an RSA key) makes the fallback clause re-enter with identical arguments, producing an unbounded tail-recursive loop that never returns and never crashes.
An application that derives a shared secret from an externally supplied peer public key without first checking that the peer key's type and curve match its own key can be driven into this loop by an attacker-controlled JWK, pinning an Erlang scheduler at 100% CPU. Repeated requests exhaust the available schedulers, resulting in a denial of service.
This issue affects jose: from 1.5.0 before 1.11.13.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| josepotatosalad | affected: 1.5.0 to < 1.11.13 | See vendor advisory |
| potatosalad/erlang-josepotatosalad | affected: 7b80b9f55b9898e1a6901ce136061b241b021d7c to < 26182a7de63b91550035d3f08741f7d17f1f675a | 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.
Sources and remediation references
- https://www.cve.org/CVERecord?id=CVE-2026-65628
- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-fpj2-9h59-32pp
- https://cna.erlef.org/cves/CVE-2026-65628.html
- https://osv.dev/vulnerability/EEF-CVE-2026-65628
- https://github.com/potatosalad/erlang-jose/commit/7b80b9f55b9898e1a6901ce136061b241b021d7c
- https://github.com/potatosalad/erlang-jose/commit/26182a7de63b91550035d3f08741f7d17f1f675a