CVE-2026-97040
Cgo directive injection via .syso files disguised as Go object files in cmd/go and cmd/link
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.
Exploit likelihood
What each source reports
CVE ListNo score
Cgo directive injection via .syso files disguised as Go object files in cmd/go and cmd/link
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.
- Record
CVE-2026-97040- Updated
- 2026-11-11
EUVDEUVD-2026-123105No score
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.
- Record
EUVD-2026-123105- Updated
- 2026-11-11
GitHub AdvisoriesGHSA-9767-p5x8-v2p2No score
Building a package containing a crafted ".syso" file could bypass cgo flag validation and inject...
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.
- Record
GHSA-9767-p5x8-v2p2- Updated
- 2026-11-11
NVDNo score
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.
- Record
CVE-2026-97040- Updated
- 2026-11-11
OSVDEBIAN-CVE-2026-97040No score
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.
- Record
DEBIAN-CVE-2026-97040- Updated
- 2026-11-11
OSVGO-2026-6851No score
Cgo directive injection via .syso files disguised as Go object files in cmd/go and cmd/link
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.
- Record
GO-2026-6851- Updated
- 2026-11-11
OSVopenSUSE-SU-2026:12529-1No score
go1.26-1.26.11-1.1 on GA media
These are all security issues fixed in the go1.26-1.26.11-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12529-1- Updated
- 2026-11-12
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
golang-1.19Debian:12 | All versions, plus listed versions 1.19.10-11.19.10-21.19.11-11.19.12-11.19.12-2 Show 7 moreShow less1.19.12-2~bpo11+11.19.12-2~bpo12+11.19.13-11.19.13-1~bpo11+11.19.13-1~bpo12+11.19.8-21.19.9-1 | None known |
golang-1.24Debian:13 | All versions, plus listed versions 1.24.12-11.24.13-11.24.13-21.24.4-11.24.4-2 Show 5 moreShow less1.24.4-31.24.4-41.24.7-11.24.8-11.24.9-1 | None known |
golang-1.26Debian:14 | All versions, plus listed versions 1.26.0-11.26.1-11.26.10-11.26.10-1~bpo13+11.26.11-1 Show 23 moreShow less1.26.2-11.26.2-21.26.2-31.26.3-11.26.3-1~bpo13+11.26.3-21.26.3-2~bpo13+11.26.4-11.26.4-1~bpo13+11.26.5-11.26.5-1~bpo13+11.26.6-11.26.6-21.26.7-11.26.7-1~bpo13+11.26.8-11.26.8-1~bpo13+11.26.8-21.26.9-11.26.9-1~bpo13+11.26~rc2-11.26~rc3-11.26~rc3-2 | None known |
golang-1.27Debian:14 | All versions, plus listed versions 1.27.0-11.27.0-1~bpo13+11.27.1-11.27.1-21.27.1-2~bpo13+1 Show 9 moreShow less1.27.2-11.27.2-1~bpo13+11.27.2-1~bpo13+21.27.3-11.27.3-1~bpo13+11.27.4-11.27~rc1-11.27~rc2-11.27~rc3-1 | None known |
toolchainGo | before 1.26.11, 1.27.0-0 up to 1.27.4 | 1.26.111.27.4 |
go1.26openSUSE:Tumbleweed From an advisory covering 12 CVEs | before 1.26.11-1.1 | 1.26.11-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, published, references | EUVD, OSV | |
| published | EUVD, NVD, OSV | |
| aliases, references | GitHub Advisories | |
| affected | OSV | |
| aliases | EUVD | |
| description, products, references | CVE List | |
| affected, aliases, description, facts, references, title | OSV | |
| first indexed | OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-97040 is a vulnerability with no CVSS score yet in Go Toolchain Cmd/go, published November 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 15th percentile. Fixed in toolchain 1.26.11.
References
go.dev/cl/862153
groups.google.com/g/golang-announce/c/iY8TY0wWgbM
pkg.go.dev/vuln/GO-2026-6851
nvd.nist.gov/vuln/detail/CVE-2026-97040
github.com/advisories/GHSA-9767-p5x8-v2p2
Show 13 moreShow less
security-tracker.debian.org/tracker/CVE-2026-97040
suse.com/security/cve/CVE-2026-97033