# CVE-2026-97033: Unexpected code execution via --sysroot, -target, -isysroot, -Wl,-syslibroot, and -x cgo flags in cmd/go


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 11 Nov 2026
- **Updated:** 11 Nov 2026
- **Also known as:** ALPINE-CVE-2026-97033, DEBIAN-CVE-2026-97033, GHSA-428h-9j26-5fcf, GO-2026-6858, UBUNTU-CVE-2026-97033

## What is CVE-2026-97033?

CVE-2026-97033 is a vulnerability in cmd/go, published on 11 Nov 2026. 

### Official description

Building a malicious package that uses cgo could cause arbitrary code execution at build time through several compiler and linker flags permitted in "#cgo" directives. Specifically, "--sysroot" in GCC and Clang relocates compiler subprograms, spec files, and CRT startup objects to an attacker-controlled directory; "-target" in Clang falls back to executing target helper tools from the current working directory when not found in PATH; "-isysroot" and "-Wl,-syslibroot" can pass a regular file on disk to GNU ld.bfd, which interprets it as a positional linker script; and "-x" permitted specifying arbitrary compiler input languages beyond those supported by cgo. "--sysroot" and "-target" are now disallowed in "#cgo" flags, "-isysroot" and "-Wl,-syslibroot" are verified not to point to regular files, and "-x" is restricted to the C, C++, Objective-C, and assembler languages supported by cgo.

## Which versions are affected by CVE-2026-97033?

1 open source package ship an affected version, including toolchain.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `toolchain` | Go | All versions | 1.26.11, 1.27.4 |

## How do I fix CVE-2026-97033?

Upgrade toolchain to a fixed version for your release line: 1.26.11 or 1.27.4.

## Is CVE-2026-97033 being exploited?

There is no known exploitation of CVE-2026-97033 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97033 and fix it if it is affected.

What it is: CVE-2026-97033 is a vulnerability in cmd/go, published on 11 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-97033 in the wild and no public exploit code.

Affected packages and fixed versions:
- toolchain (Go): affected all versions; fixed in 1.26.11, 1.27.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-97033/ (Markdown: https://insights.sbomify.com/CVE-2026-97033/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97033
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97033
- OSV: https://osv.dev/vulnerability/CVE-2026-97033

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97033/
Summaries are generated and may contain mistakes; the official description above is the record.