AZL-113435: CVE-2026-97035 affecting package golang 1.26.11-1
When using Clang or GCC, building a malicious package that uses cgo could cause unexpected code execution at build time or write files to arbitrary directories via "-gen-" or "-gnat" flags in "#cgo" directives. The "-g" wildcard in the compiler and linker flag allowlists previously matched Clang's two-argument "-gen-cdb-fragment-path <dir>" flag and GCC's two-argument "-gnatO <file>" flag, permitting compilation database fragments and sidecar output files to be written to arbitrary directories and desynchronizing flag argument parsing between the go command and the compiler driver so that subsequent arguments could be passed as unvalidated positional inputs to the linker. "-gen-" and "-gnat" flags are now disallowed in "#cgo" compiler and linker flags.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Build environments using the Go toolchain with Clang or GCC are exposed when they build an untrusted or malicious package that uses cgo. The issue occurs during the build process, not necessarily when running the resulting program.
What does an attacker need to exploit it?
An attacker needs to cause a target to build a malicious cgo package containing crafted #cgo compiler or linker directives. The crafted directives use the previously allowed -gen-* or -gnat* flag patterns.
What could exploitation allow?
A malicious package could cause unexpected code execution at build time. It could also write compilation database fragments or sidecar output files to arbitrary directories, and cause subsequent arguments to reach the linker as unvalidated positional inputs.
What changed in the fixed package?
The Go command now disallows -gen-* and -gnat* flags in #cgo compiler and linker flags. This prevents the affected Clang and GCC two-argument flag forms from matching the prior -g* allowlist wildcard.