CVE-2026-116587: Go JOSE: DoS when parsing JWKs that contain RSA keys

Vulnerability summary

CVE-2026-116587 is a high (CVSS 7.5) Inefficient Algorithmic Complexity vulnerability in go-jose. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 30.6% of scored vulnerabilities.

Timeline

1. 26-10-2026
   PublishedVulnerability first disclosed.
2. 27-10-2026
   Last modifiedVulnerability information updated.

Description

Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.6, go-jose parses attacker-controlled RSA modulus and prime values from JWKs without enforcing size and consistency bounds before passing them to crypto/rsa.PrivateKey.Validate. On Go 1.24 and later, crafted large or degenerate RSA parameters can make that validation consume cubic CPU time, allowing remote denial of service in applications that parse JWKs from untrusted sources. This issue is fixed in version 4.1.6.

• CWE-407Inefficient Algorithmic ComplexityAn algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.