Investigate in your agent.

Turn this advisory into a focused investigation. Ask your agent to check your project’s versions, explain the evidence, and suggest a compatible fix.

Your agent needs remote MCP support and access to https://cve.new/mcp.

Read the setup guide

Skip to content
cve.newCreate a CVE report
Check your stack
CVE-2026-97040

Cgo directive injection via .syso files disguised as Go object files in cmd/go and cmd/link

Products / packages Go toolchain cmd/go · Go toolchain cmd/link · toolchain

Published

Share

Severity and exploitation

Not in CISA KEVNo CVSS score

KEV coverage does not rule out exploitation.

KEV checked 14/11/2026, 20:55:32 UTC

Severity

unknown

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Package fixes recorded

Fix versions are recorded for 1 of 1 mapped packages. Check each release branch and any separate product guidance.

What this means

Building a package containing a crafted ".syso" file could bypass cgo flag validation and inject arbitrary linker flags when linking.

Source excerpt · OSV

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Go toolchain · Go

cmd/go

2 ranges
Go version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

0 → before 1.26.11

semver versions

1.27.0-0 → before 1.27.4

semver versions

unaffected

unknown

Other versions: unaffected

Go toolchain · Go

cmd/link

2 ranges
Go version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

0 → before 1.26.11

semver versions

1.27.0-0 → before 1.27.4

semver versions

unaffected

unknown

Other versions: unaffected

Packages

Compare each installed version with the publisher’s affected ranges. Where a fix is recorded, choose the appropriate release branch and test compatibility before upgrading.

toolchain Go
Affected range Recorded fix
Earlier releases before 1.26.11Semantic versions1.26.11
From 1.27.0-0 before 1.27.4Semantic versions1.27.4

Version evidence: OSV · GO-2026-6851

View original version evidence (0 explicit versions)

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

Use the recorded fix for your release branch. Review the publisher’s instructions and test compatibility before upgrading.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher 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.

References

4 sources
go.dev/cl/862153
Source referenceGo
go.dev/issue/82570
Source referenceGo
groups.google.com/g/golang-announce/c/iY8TY0wWgbM
Source referenceGo
pkg.go.dev/vuln/GO-2026-6851
Security advisoryGo

Inside the record

Evidence available

Package identity
Version evidence
Remediation guidance · not supplied
Weakness classification · not supplied
Additional publishers · not supplied

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-97040

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →
Contributing organizations · 1
Go

Assigning organization

2026-11-11

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.