CVE-2026-65631 Inefficient Algorithmic Complexity in erlang-jose allows an unauthenticated remote attacker to cause a CPU-exhaustion denial of service by s
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-65631?
CVE-2026-65631 is a medium-severity vulnerability in potatosalad jose, published on 26 Oct 2026.
Official description
Inefficient Algorithmic Complexity in erlang-jose allows an unauthenticated remote attacker to cause a CPU-exhaustion denial of service by submitting a crafted RSA JSON Web Key.
When an application parses an untrusted JWK through the public jose_jwk:from_binary/1 or jose_jwk:from_map/1 API (or the Elixir wrappers JOSE.JWK.from_binary/1 and JOSE.JWK.from_map/1), an RSA private key that supplies d, e, and n but omits all Chinese Remainder Theorem parameters (p, q, dp, dq, qi) is routed into convert_sfm_to_crt/1, which tries to recover the missing primes by factoring the modulus. The three integers are read straight from the base64url input and are never validated as a real RSA key. When the modulus cannot be split into two factors (for example, when it is itself prime), the search loop convert_sfm_to_crt_find_p/6 performs a modular exponentiation over the attacker-sized modulus on every iteration and never succeeds. A single request of a few hundred bytes forces close to one CPU-second of work before an internal one-second watchdog kills the worker, and a larger modulus raises the cost further. By flooding such requests an attacker can saturate every scheduler and deny service, without credentials, a valid RSA key, or any special configuration.
This issue affects jose: from 1.7.7 before 1.11.13.
Weakness: CWE-407
Which versions are affected by CVE-2026-65631?
1 open source package ship an affected version, including jose.
| Package | Affected | Fixed in |
|---|---|---|
jose Hex | From 1.7.7 | 1.11.13 |
How do I fix CVE-2026-65631?
Upgrade jose to 1.11.13 or later.
Is CVE-2026-65631 being exploited?
There is no known exploitation of CVE-2026-65631 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-65631, EEF-CVE-2026-65631, GHSA-3m45-vrpj-xmrq, UBUNTU-CVE-2026-65631.