CVE-2026-91780 in Binutils
Summary
by MITRE • 09/15/2026
A weakness has been identified in GNU Binutils 2.47. This impacts the function elf_link_add_object_symbols of the file bfd/elflink.c. Executing a manipulation can lead to null pointer dereference. The attack needs to be launched locally. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through a bug report but has not responded yet.
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Analysis
by VulDB Data Team • 09/15/2026
The identified vulnerability resides within GNU Binutils version 2.47, specifically affecting the elf_link_add_object_symbols function located in the bfd/elflink.c source file. This component is critical to the Binary File Descriptor library, which handles various object file formats including ELF during the linking process. The core technical flaw involves a null pointer dereference condition that can be triggered through specific manipulation of input data. When the linker processes certain malformed or specially crafted object files, it fails to properly validate pointers before attempting to access them, leading to an immediate crash of the application rather than graceful error handling. This type of memory safety issue is classically categorized under CWE-476, which denotes a NULL Pointer Dereference vulnerability where software incorrectly handles a null pointer that should never be used, resulting in unexpected termination or potential code execution if combined with other conditions.
The operational impact of this flaw primarily manifests as a denial of service against the linking process. Since the attack vector requires local access to execute, an attacker must have some level of authenticated access to the system running GNU Binutils. By providing a maliciously constructed object file that triggers the null pointer dereference within elf_link_add_object_symbols, an adversary can cause the linker utility to crash abruptly. While this does not directly result in remote code execution or privilege escalation on its own due to the nature of the memory error and the local requirement, it disrupts build processes, continuous integration pipelines, and development workflows that rely on automated linking steps. The availability of a public exploit significantly lowers the barrier for entry, allowing individuals with limited technical expertise to reproduce this denial-of-service condition effectively against systems running the affected version.
From a threat intelligence perspective, this vulnerability aligns with techniques observed in the MITRE ATT&CK framework related to resource hijacking or disruption via local execution. Although GNU Binutils is primarily a development tool and not typically exposed as a network service, its widespread use means that compromising build environments can have downstream effects on software supply chain integrity if attackers manage to inject malicious artifacts during compromised builds before the crash occurs. However, in this specific instance, the primary consequence remains system instability for the local user or process invoking the linker. The project maintainers were notified early via a bug report but had not yet responded at the time of disclosure, highlighting potential gaps in vulnerability management workflows within open-source projects that rely on volunteer contributions.
Mitigation strategies should focus primarily on version control and environment hardening until an official patch is released by the GNU Binutils team. Administrators and developers utilizing this software should immediately upgrade to a patched version once it becomes available from the official distribution channels. In the interim, restricting access to systems running vulnerable versions of Binutils can reduce the risk of exploitation by unauthorized local users. Additionally implementing strict input validation on any scripts or tools that feed object files into the linker may help prevent triggering the flaw in custom workflows. Security teams should also monitor for unusual process termination events associated with binutils processes as an indicator of potential attempted exploitation within their environments.