4.8
MEDIUM CVSS 4.0
CVE-2026-2069
ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow
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.

INFO

Published Date :

Feb. 6, 2026, 10:16 p.m.

Last Modified :

Feb. 6, 2026, 10:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-2069 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
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 LOW [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Fix a stack-based buffer overflow vulnerability in the GBNF Grammar Handler component.
  • Update ggml-org llama.cpp to the latest version.
  • Deploy the patch for the identified vulnerability.
  • Review the llama_grammar_advance_stack function for integrity.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-2069 is associated with the following CWEs:

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-2026-2069 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-2069 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]

    Feb. 06, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
    Added CVSS V2 (AV:L/AC:L/Au:S/C:N/I:N/A:P)
    Added CWE CWE-119
    Added CWE CWE-121
    Added Reference https://github.com/ggml-org/llama.cpp/
    Added Reference https://github.com/ggml-org/llama.cpp/issues/18988
    Added Reference https://github.com/ggml-org/llama.cpp/issues/18988#event-4426704865
    Added Reference https://github.com/ggml-org/llama.cpp/pull/18993
    Added Reference https://github.com/user-attachments/files/24761101/poc.zip
    Added Reference https://vuldb.com/?ctiid.344636
    Added Reference https://vuldb.com/?id.344636
    Added Reference https://vuldb.com/?submit.745263
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 4.8
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 3.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 1.7
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact