Use After Free in Ggml-Org Llama.cpp

CVE-2026-39909

llama.cpp before b8585 contains a use-after-free vulnerability in the RPC server's GRAPH_RECOMPUTE handler that allows unauthenticated remote attackers to achieve arbitrary read and write access by storing a computation graph, freeing referenced buffers, and reclaiming freed memory with attacker-controlled content. Attackers can send RPC requests to trigger re-execution of stored graphs with dangling pointers, enabling full remote code execution without requiring authentication or user interaction.

Vulnerability class: Use-After-Free

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-39909?
CVE-2026-39909 is a high-severity vulnerability in Ggml-Org Llama.cpp, classified under Use After Free. CVSS score: 8.1/10. Published 2026-08-21.
How severe is CVE-2026-39909?
High severity. CVSS v3 base score is 8.1 out of 10.