CVE-2026-2069
Unknown Unknown - Not Provided
Stack-Based Buffer Overflow in ggml-org llama.cpp GBNF Handler

Publication date: 2026-02-06

Last updated on: 2026-04-29

Assigner: VulDB

Description
A flaw has been found in ggml-org llama.cpp up to 55abc39. Impacted is the function llama_grammar_advance_stack of the file llama.cpp/src/llama-grammar.cpp of the component GBNF Grammar Handler. This manipulation causes stack-based buffer overflow. The attack needs to be launched locally. The exploit has been published and may be used. Patch name: 18993. To fix this issue, it is recommended to deploy a patch.
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Meta Information
Published
2026-02-06
Last Modified
2026-04-29
Generated
2026-06-16
AI Q&A
2026-02-07
EPSS Evaluated
2026-06-15
NVD
CVE-2026-2069
EUVD
EUVD-2026-5558
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
ggml-org llama.cpp to 55abc39 (inc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-119 The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
CWE-121 A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
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Executive Summary

This vulnerability is a flaw found in the ggml-org llama.cpp project, specifically in the function llama_grammar_advance_stack within the GBNF Grammar Handler component. It causes a stack-based buffer overflow, which means that the program writes more data to a buffer located on the stack than it can hold, potentially leading to unexpected behavior or crashes.

The vulnerability requires local access to the system to be exploited, and an exploit has already been published. To address this issue, it is recommended to apply the provided patch.

Impact Analysis

This vulnerability can impact you by allowing a local attacker to cause a stack-based buffer overflow, which may lead to denial of service or potentially other unintended behaviors depending on how the overflow is exploited.

Since the attack requires local access, remote exploitation is not possible, but an attacker with local privileges could leverage this flaw to disrupt the normal operation of the affected software.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, it is recommended to deploy the patch named 18993 that fixes the issue in the llama_grammar_advance_stack function of the GBNF Grammar Handler component.

Since the attack requires local access, limiting local user privileges and access can also help reduce risk.

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