Vulnerability DatabaseCVE-2025-8733

CVE-2025-8733:
Linux Debian vulnerability analysis and mitigation

Overview

A vulnerability has been identified in GNU Bison up to version 3.8.2 (CVE-2025-8733), discovered on August 8, 2025. The issue affects the _obstackvprintf_internal function in the obprintf.c file, leading to an assertion failure. The vulnerability has been rated as problematic and can be triggered locally (VulDB, NVD).

Technical details

The vulnerability manifests as an assertion failure in the _obstackvprintfinternal function at line 158 of obprintf.c. The assertion that fails is 'size == (newf.ofile.file.file.IOwriteend - newf.ofile.file.file.IOwrite_base)', indicating an inconsistency in the obstack's internal buffer management system. The issue has received a CVSS v3.1 base score of 3.3 LOW, with a vector of AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L (GitHub Issue).

Impact

When exploited, the vulnerability causes an immediate program termination with SIGABRT signal, resulting in a denial of service condition. The impact primarily affects availability, as the assertion failure leads to program crashes during grammar processing (GitHub Issue, VulDB).

Mitigation and workarounds

Currently, there are no known official fixes or mitigations available for this vulnerability. It is suggested to consider replacing the affected version with an alternative product until a patch is released (VulDB).

Community reactions

The vulnerability was discovered and reported by security researchers Xudong Cao (UCAS) and Yuqing Zhang (UCAS, Zhongguancun Laboratory). The issue has been documented in multiple security databases and tracking systems (GitHub Issue).