CVE-2026-33996
Description
A flaw was found in LibJWT, a C JSON Web Token Library. When parsing JSON Web Key (JWK) files for RSA-PSS, the library did not correctly handle cases where NULL values were encountered instead of expected string values. An attacker could exploit this vulnerability by providing a specially crafted JWK file containing integers in fields that anticipate strings. This could lead to a denial of service, impacting the availability of systems using the affected library.
Statement
The LibJWT is only shipped with community products. The 2.x series and before of LibJWT does not have JWK parsing, so they are not affected.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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