CVE-2025-11495 is a heap-based buffer overflow vulnerability identified in GNU Binutils version 2.45, a widely used collection of binary tools including the linker. The vulnerability resides in the elf_x86_64_relocate_section function within the elf64-x86-64.c source file, which handles relocation processing for x86_64 ELF binaries. Improper handling of relocation data leads to a heap overflow condition, potentially allowing an attacker to corrupt memory. The attack requires local access and limited privileges, as it targets the linker component typically invoked during software compilation or binary manipulation. No user interaction or elevated privileges beyond local access are necessary, but the attacker must execute the malicious input locally. The vulnerability has been publicly disclosed with a patch identified by commit 6b21c8b2ecfef5c95142cbc2c32f185cb1c26ab0. The CVSS 4.8 score reflects the medium severity, considering the local attack vector, low complexity, and limited impact on confidentiality, integrity, and availability. No known exploits are currently active in the wild, but the public disclosure increases the risk of future exploitation. The vulnerability affects primarily Linux and Unix-like systems using GNU Binutils 2.45, which is common in development and production environments that compile or link ELF binaries.

The heap-based buffer overflow in GNU Binutils 2.45 can lead to memory corruption, which may allow an attacker to crash the linker process or potentially execute arbitrary code with the privileges of the user running the linker. Since the attack is local, the impact is limited to users or processes with access to the affected system. However, in development environments or build servers where Binutils is used extensively, exploitation could disrupt software compilation or introduce malicious code during the build process. This could affect software supply chain integrity and reliability. The vulnerability does not directly impact remote systems or require network access, limiting its scope. Nonetheless, in environments where multiple users share build infrastructure, a malicious insider or compromised local user could leverage this flaw to escalate privileges or disrupt operations. The medium severity rating reflects these factors, indicating moderate risk primarily to confidentiality and integrity within affected systems.

To mitigate CVE-2025-11495, organizations should promptly apply the official patch referenced by commit 6b21c8b2ecfef5c95142cbc2c32f185cb1c26ab0 to all affected GNU Binutils 2.45 installations. Additionally, restrict local access to build and compilation environments to trusted users only, minimizing the risk of local exploitation. Employ strict user privilege separation and monitoring on systems where Binutils is used to detect anomalous linker invocations or crashes. Integrate security scanning and code integrity checks in build pipelines to detect potential tampering resulting from exploitation attempts. Consider using containerized or isolated build environments to limit the impact of any compromise. Regularly update GNU Binutils and related toolchains to the latest versions to benefit from ongoing security improvements. Finally, maintain comprehensive logging and alerting on build servers to quickly identify and respond to suspicious activities related to linker processes.