CVE-2026-97040: Go toolchain cmd/go · Code Injection
Affects Go toolchain cmd/goSource CVE Database V5
Not known to be exploited : upgrade to 1.27.4 or 1.26.11 when convenient.
Data as of 11 Nov 2026, 03:33 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in 1.27.4, 1.26.11
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade cmd/go and cmd/link to 1.27.4 or 1.26.11.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Go toolchaincmd/go | Affected
| Fixed in
|
| Go toolchaincmd/go | Affected
| Fixed in
|
| Go toolchaincmd/link | Affected
| Fixed in
|
| Go toolchaincmd/link | Affected
| Fixed in
|
Gocmd/gopkg:golang/cmd/goOther threats | Affected
| Fixed in
|
Gocmd/linkpkg:golang/cmd/linkOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Building a package containing a crafted ".syso" file could bypass cgo flag validation and inject arbitrary linker flags when linking. When loading ".syso" entries from a package archive, the linker only checked for recognized host object headers (ELF, Mach-O, PE, and XCOFF) before falling through to Go object parsing. A ".syso" file beginning with a "go object" header was parsed as a Go compiler object, allowing untrusted cgo metadata directives (such as "cgo_ldflag" or "cgo_dynamic_linker") embedded in the ".syso" file to be passed to the external linker without validation. Additionally, ".syso" filenames longer than 16 bytes lost their ".syso" extension when truncated in archive headers, and unrecognized ".syso" formats forced external linking in pure-Go builds. The linker now rejects ".syso" files that are not recognized host object formats, and "cmd/go" and "cmd/pack" preserve the ".syso" suffix when truncating long archive member names.