CVE-2026-43627
Description
A flaw was found in llama.cpp. An integer overflow vulnerability exists in the llama_batch_init() function due to unchecked multiplications during memory allocation. Attackers can provide specially crafted input parameters, leading to heap corruption. This could potentially allow for arbitrary code execution through subsequent operations that write beyond allocated memory boundaries.
Statement
Exploitation requires convincing a user or local process to execute inference workloads using maliciously oversized batch sizing parameters, leading to an arithmetic overflow during memory allocation and subsequent heap corruption. Full impact across Confidentiality, Integrity, and Availability (C:H, I:H, A:H) is possible if local memory execution controls fail, potentially resulting in arbitrary code execution within the application context. Deployments operating strictly with validated, bounded batch size inputs or running non-interactive server pipelines where batch parameters are hard-coded or strictly validated are unaffected.
Mitigation
To reduce the risk, avoid processing untrusted or malicious input with applications that use the llama.cpp library. Deploying applications that utilize llama.cpp within a sandboxed environment can further limit the potential impact of successful exploitation.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
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