LibreOffice Heap-Based Buffer Overflow Vulnerability Allows Remote Code Execution
A heap-based buffer overflow in LibreOffice's dBase file parsing component, disclosed by Zero Day Initiative, allows remote attackers to execute arbitrary code.
A critical heap-based buffer overflow vulnerability has been identified in the dBase file parsing component of LibreOffice, according to an advisory from the Zero Day Initiative (ZDI). This flaw, tracked as CVE-2026-76181, carries a CVSS score of 7.8 and could allow remote attackers to execute arbitrary code on vulnerable systems.
The vulnerability stems from improper validation of user-supplied data within the parsing of dBase index files, which are often referenced by .odb database files. When processing these files, LibreOffice fails to adequately check the length of data before copying it into a heap-based buffer. This oversight can be exploited by an attacker to overwrite adjacent memory, potentially leading to code execution in the context of the current process.
Exploitation of this vulnerability requires user interaction. Attackers must trick a user into opening a specially crafted malicious file or visiting a malicious web page that triggers the vulnerable parsing mechanism. Once initiated, the buffer overflow can be leveraged to achieve arbitrary code execution, giving the attacker control over the affected LibreOffice process.
LibreOffice has released an update to address this security concern. Users are strongly advised to update their installations to the latest version to mitigate the risk. Further details on the patch and the specific version addressing CVE-2026-76181 can be found on the official LibreOffice security advisories page.
The disclosure timeline indicates that the vulnerability was initially reported to the vendor on August 20, 2026. Following coordinated disclosure efforts, the advisory was publicly released on November 6, 2026, with an update to the advisory also published on the same date. The vulnerability was reported by an anonymous researcher.
This discovery highlights the ongoing risks associated with parsing complex file formats, even in widely used open-source applications. Software developers must maintain rigorous input validation and memory management practices to prevent such vulnerabilities from being introduced and exploited. The ZDI's role in discovering and facilitating the responsible disclosure of such flaws remains crucial for enhancing software security across the ecosystem.
Users who handle dBase files or .odb databases within LibreOffice should exercise caution when opening documents from untrusted sources. Applying the latest security patches promptly is the most effective defense against this and similar vulnerabilities. The widespread adoption of LibreOffice makes timely patching essential to protect a large user base from potential attacks.