ggml-org llama.cpp gguf_init_from_file_impl heap-based overflow

Summaryinfo

A vulnerability, which was classified as critical, was found in ggml-org llama.cpp. This vulnerability affects the function gguf_init_from_file_impl. Executing a manipulation can lead to heap-based overflow. This vulnerability is handled as CVE-2026-27940. It is possible to launch the attack on the local host. There is not any exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability has been found in ggml-org llama.cpp (affected version not known) and classified as critical. This vulnerability affects the function gguf_init_from_file_impl. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

llama.cpp is an inference of several LLM models in C/C++. Prior to b8146, the gguf_init_from_file_impl() in gguf.cpp is vulnerable to an Integer overflow, leading to an undersized heap allocation. Using the subsequent fread() writes 528+ bytes of attacker-controlled data past the buffer boundary. This is a bypass of a similar bug in the same file - CVE-2025-53630, but the fix overlooked some areas. This vulnerability is fixed in b8146.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-27940 since 02/25/2026. The exploitation appears to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 302198 (Linux Distros Unpatched Vulnerability : CVE-2026-27940), which helps to determine the existence of the flaw in a target environment.

Applying the patch b8146 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at Tenable (302198). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• ggml-org

Name

• llama.cpp

Website

• Product: https://github.com/ggml-org/llama.cpp/

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Once again VulDB remains the best source for vulnerability data.

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