Unexpected code execution via escaped quotes in //go:cgo_ldflag in cmd/go and cmd/compile

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 cgo could bypass "#cgo LDFLAGS" validation and cause unexpected code execution at build time, or cause the go command to panic, via crafted quoting in "//go:cgo_ldflag" directives. When "cmd/cgo" generates "_cgo_gotypes.go", it quotes each "#cgo LDFLAGS" argument with strconv.Quote in a "//go:cgo_ldflag" directive, but "cmd/compile" and "cmd/go" parsed those directives by splitting on raw quote characters without handling backslash escapes or unquoting the string. This mismatch allowed disallowed linker flags or unvalidated linker search paths to be smuggled past the go command's flag checks and passed to the external linker. In addition, deduplicating LDFLAGS in the go command could panic with an out-of-bounds slice index when a prefix of the flag list matched near the end of the slice. "cmd/compile" and "cmd/go" now properly handle backslash-escaped quotes and unquote "//go:cgo_*" pragma strings with strconv.Unquote, and the slice bounds check…

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-2026-6848

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# Patch Next advisory brief: CVE-2026-97043

Advisory: Unexpected code execution via escaped quotes in //go:cgo_ldflag in cmd/go and cmd/compile
IDs: CVE-2026-97043
Record: https://patchnext.com/advisories/cve-2026-97043 (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-2026-6848 (OSV record GO-2026-6848 lists affected ranges: Go toolchain >=0 =1.27.0-0 <1.27.4 (fixed))

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