CVE-2026-39909
llama.cpp Use-After-Free in RPC GRAPH_RECOMPUTE Handler
Description
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.
INFO
Published Date :
Aug. 21, 2026, 5:16 p.m.
Last Modified :
Aug. 21, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-39909
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update llama.cpp to a patched version.
- Disable the RPC server if not needed.
- Restrict network access to the RPC server.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-39909.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-39909 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-39909
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-39909 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-39909 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 21, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/ggml-org/llama.cpp', 'vendor': 'ggml-org', 'product': 'llama.cpp', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': 'b8585', 'versionType': 'custom'}], 'packageURL': 'pkg:github/ggml-org/llama.cpp', 'defaultStatus': 'unaffected'}] Added Description 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. Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-416 Added Reference https://github.com/ggml-org/llama.cpp/commit/389c7d4955ba55c7418afaebf7c23d9ed64ef707 Added Reference https://github.com/ggml-org/llama.cpp/pull/21175 Added Reference https://github.com/ggml-org/llama.cpp/releases/tag/b8585 Added Reference https://www.vulncheck.com/advisories/llama-cpp-use-after-free-in-rpc-graph-recompute-handler