CVE-2026-27140: Code execution vulnerability in SWIG code generation in cmd/go

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-08 · updated 2026-09-10
Weakness: CWE-863

Description

SWIG file names containing 'cgo' and well-crafted payloads could lead to code smuggling and arbitrary code execution at build time due to trust layer bypass.

Affected products

Go: before 1.25.9; from 1.26.0 before 1.26.2 — fixed in 1.25.9, 1.26.2

How to fix

Upgrade to a fixed version: Go 1.25.9, 1.26.2. Check the vendor advisory for mitigations.

References

https://go.dev/cl/763768
https://go.dev/issue/78335
https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU
https://pkg.go.dev/vuln/GO-2026-4871
https://access.redhat.com/errata/RHSA-2026:10217
https://access.redhat.com/errata/RHSA-2026:10219
https://access.redhat.com/errata/RHSA-2026:10704
https://access.redhat.com/errata/RHSA-2026:16021
https://access.redhat.com/errata/RHSA-2026:16024
https://access.redhat.com/errata/RHSA-2026:16494
https://access.redhat.com/errata/RHSA-2026:16497
https://access.redhat.com/errata/RHSA-2026:16498

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