The vulnerability stems from uncontrolled recursion in the json-schema-to-grammar.cpp component of llama.cpp, a flaw classified as CWE-674. When triggered, the recursion can exhaust stack or heap resources, causing the application to crash or become unresponsive, which results in a denial of service attack. This weakness is limited to the parsing logic and does not provide direct code execution or data exfiltration capabilities.

llama.cpp releases b5693 and earlier are affected. The vulnerability resides in common/json-schema-to-grammar.cpp of those versions, and any deployment that compiles or runs these releases may be impacted.

The CVSS score of 7.5 indicates a high severity and the EPSS score is not available, so the current exploitation likelihood is unknown but could be moderate to high if the component is exposed. The vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that the attack vector requires supplying a crafted JSON schema to the parser, which could be done directly if the application processes user‑supplied schemas or indirectly through a service that accepts such input. Once triggered, the attacker can force the application to consume excessive resources, degrading service availability.