CVE-2026-89086: Critical severity jose vulnerability
In the jose package before 0.11.0 for OCaml, library calls to validate an RSA signature only confirm that PKCS #1 decoding succeeds, and proceed to declare the signature valid without the required steps that involve the public key.
Affected Software
Event History
Frequently Asked Questions
Which deployments are affected?
OCaml applications using the jose package before version 0.11.0 are affected when they rely on its RSA signature validation calls.
Does exploitation require authentication or user interaction?
The provided vector indicates network reachability, low attack complexity, no required privileges, and no user interaction.
What is the immediate remediation?
Upgrade the jose package to version 0.11.0 or later. The issue affects versions before 0.11.0.
How can I determine whether my application is exposed?
Check whether the application depends on jose before 0.11.0 and uses the library to validate RSA signatures. Such validation may accept signatures after PKCS #1 decoding succeeds without completing the required public-key-related checks.