CVE-2026-97035 Unexpected code execution and arbitrary file write via Clang -gen-* and GCC -gnat* flags in cgo in cmd/go
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-97035?
CVE-2026-97035 is a vulnerability in cmd/go, published on 11 Nov 2026.
Official description
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.
Which versions are affected by CVE-2026-97035?
1 open source package ship an affected version, including toolchain.
| Package | Affected | Fixed in |
|---|---|---|
toolchain Go | All versions | 1.26.11, 1.27.4 |
How do I fix CVE-2026-97035?
Upgrade toolchain to a fixed version for your release line: 1.26.11 or 1.27.4.
Is CVE-2026-97035 being exploited?
There is no known exploitation of CVE-2026-97035 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-97035, DEBIAN-CVE-2026-97035, GHSA-6f8j-v7cw-qxpp, GO-2026-6856, UBUNTU-CVE-2026-97035.