Linker flag injection via cgo_import_dynamic and PE DLL names in cmd/cgo, cmd/compile, and cmd/link

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Building a malicious package that uses "//go:cgo_import_dynamic" or links against a crafted PE object on Windows could pass unsafe library arguments to the external linker. The compiler only checked the first character of the library name in "//go:cgo_import_dynamic" directives and skipped validation in cgo-generated files. In addition, on Windows, "cmd/cgo" and "cmd/link" did not validate imported DLL names extracted from PE object files before emitting "-l " flags for the external linker, allowing a crafted DLL name containing ".." path traversal or special characters to reference arbitrary files on disk. The compiler now validates every character of the library name in "//go:cgo_import_dynamic" directives (including in cgo-generated files on Windows) and rejects ".." path traversal, and "cmd/cgo" and "cmd/link" reject PE imported DLL names containing path separators, "..", ":", or leading "-" or "@".

Published by the source

11 Nov 2026, 02:51 UTC

Last modified by the source

11 Nov 2026, 03:15 UTC

Source last checked

11 Nov 2026, 07:20 UTC

1. Revision 1 · created · 11 Nov 2026

   Published from osv record GO-2026-6849

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# Patch Next advisory brief: CVE-2026-97042

Advisory: Linker flag injection via cgo_import_dynamic and PE DLL names in cmd/cgo, cmd/compile, and cmd/link
IDs: CVE-2026-97042
Record: https://patchnext.com/advisories/cve-2026-97042 (revision 1, source checked 11 Nov 2026, 07:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: toolchain 1.27.4, 1.26.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go toolchain: affected < 1.26.11; >= 1.27.0-0, < 1.27.4; fixed in 1.26.11, 1.27.4

## Suggested inspection (read-only)
- Go toolchain: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on toolchain.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GO-2026-6849 (OSV record GO-2026-6849 lists affected ranges: Go toolchain >=0 =1.27.0-0 <1.27.4 (fixed))

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