Executive brief
GNU Binutils is a collection of binary tools used by developers and build systems to compile and link software. A flaw in how Binutils processes malformed input files can cause the linker to crash with a null pointer dereference, disrupting builds and potentially preventing software from being compiled.
Technical details
The vulnerability is a null pointer dereference in the elf_x86_allocate_dynrelocs function within bfd/elfxx-x86.c, triggered when processing malformed dynamic relocation information in ELF object files. The root cause stems from the dynamic relocation allocation path failing to properly validate or initialize section-related variables (htab, sreloc) when handling excluded or malformed sections. Attack requires local file access; an attacker can craft a malicious ELF object file that triggers the crash when processed by the linker. The flaw affects only local build environments with the ability to provide crafted input files. Patches have been committed to the master branch (commits d1268210b6f6, 471130b39c0, and others), and upgrading to version 2.48 or later resolves the issue.
Affected products
- GNU Binutils 2.47
Timeline
- 2026-07-28: disclosed: Vulnerability reported to Sourceware Bugzilla as bug 34448
- 2026-07-30: patched: First patch committed (d1268210b6f6)
- 2026-09-15: advisory: CVE-2026-91782 published