CVE-2026-116124

A flaw was found in libgsf. A heap-based buffer overflow vulnerability exists in the OLE2 document parser within the ole_info_read_metabat function. A remote attacker could exploit this flaw by enticing a user to open a specially crafted file. Successful exploitation could lead to arbitrary code execution or cause an application crash, resulting in a Denial of Service (DoS).

This vulnerability is rated as an Important impact because successful exploitation allows potential code execution or process termination under the privileges of the executing user. In Red Hat Enterprise Linux, libgsf is utilized by graphical utilities and document processing tools to handle structured storage formats. Exploitation requires a user or backend service to parse an untrusted, maliciously formed OLE2 file, meaning the flaw cannot be triggered without direct file ingestion. The blast radius remains limited to the permissions of the invoking application.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

--- CME Mitigation Guidance (2026-11-02) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.

The highest-value action is to prevent untrusted OLE2 document ingestion by applications and backend services linking libgsf: upgrade to libgsf > 1.14.60 (or the fixed Libgsf builds), which fixes heap-based buffer overflow in ole_info_read_metabat during OLE2 parsing, closing crafted OLE2 document file ingestion. Until patched, this is a concern on Linux systems running applications or automated services processing OLE2 files via libgsf, so restrict ingestion of untrusted or externally sourced OLE2 documents across services and user workflows using libgsf. As a compensating measure, randomize user-space memory layouts via ASLR to hinder predictable heap exploitation, enforce full RELRO and PIE to protect Global Offset Tables and binary mappings, deploy Control Flow Integrity or shadow call stacks to block indirect control-flow hijacking, enable FORTIFY_SOURCE to abort processes on detected buffer overflow conditions, confine document parsing processes within restricted SELinux domains in enforcing mode, and restrict parser process filesystem access using Landlock LSM sandboxing. These controls limit blast radius and contain exploitation, but they do not fix the underlying heap-based buffer overflow — apply the upstream patch to fully remediate.

Highest-impact CME: CME-301 SELinux (Enforcing Mode) (medium)