The vulnerability resides in the Jinja Minja Template parser of ggml-org llama.cpp and is triggered when a specially crafted input such as "{{9|9|{" reaches an assertion in common/jinja/parser.cpp. The assertion failure causes the program to crash, which results in a local denial of service. The weakness is identified as CWE-617 and relies on improper handling of malformed template data. No privilege escalation or data disclosure results from the failure—only termination of the affected process. The impact is limited to local execution environments that invoke the vulnerable parser.

The affected software is ggml-org llama.cpp, specifically the implementation of the Jinja Minja parser in the file common/jinja/parser.cpp. The issue was discovered in commit e15efe0; no specific version ranges are published, so any build that includes this unmodified code may be vulnerable. Users deploying llama.cpp should verify whether the parser component is present in their build and whether any fixes have been applied upstream.

The CVSS score of 4.8 indicates a moderate severity impact. The EPSS score is not available, suggesting public data is insufficient to quantify exploit likelihood. The vulnerability is not listed in CISA’s KEV catalog, and no known remote exploitation pathway is documented. The attack requires local access to the system and the execution of a crafted template string. Because the vulnerability merely triggers a crash rather than a more complex compromise, the overall risk is considered moderate; however, in environments where uptime is critical, the impact of repeated failures can be significant.