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TI-2026-21590 Aliases CVE-2026-27140GHSA-5w89-2c2x-6x66

Code execution vulnerability in SWIG code generation in cmd/go

Priority MEDIUM 41CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 20 fixed, 5 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-863.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0067 52nd percentileScored 2026-11-07
Fix Partial cmd/go (Go toolchain): 1.25.9, 1.26.2Red Hat: 17 advisoriesRed Hat: 20 fixed, 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Go standard librarycmd/gobefore 1.25.9; 1.26.0-0 to before 1.26.21.25.9, 1.26.2Patch availableCNA
  • cmd/go VendorGo standard library Affected before 1.25.9; 1.26.0-0 to before 1.26.2 Fixed in 1.25.9, 1.26.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*before 1.25.9; 1.26.0 to before 1.26.2VulnerableGo standard library
  • cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* Versions before 1.25.9; 1.26.0 to before 1.26.2 Vulnerable ·Go standard library

Remediation

  • Fix · CNA cmd/go (Go toolchain) Fixed in 1.25.9, 1.26.2

Red Hat 17 advisories

  • RHSA-2026:56854 Released 2026-08-26 · Red Hat rating Important
    OpenShift Container Platform 4.16.69 bug fix and security update
    • Red Hat OpenShift Container Platform 4.16 registry.redhat.io/openshift4/aws-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/azure-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/cloud-network-config-controller-rhel9 +47
  • RHSA-2026:57408 Released 2026-08-26 · Red Hat rating Important
    OpenShift Container Platform 4.19.44 bug fix and security update
    • Red Hat OpenShift Container Platform 4.19 registry.redhat.io/openshift4/ose-apiserver-network-proxy-rhel9, registry.redhat.io/openshift4/ose-azure-workload-identity-webhook-rhel9, registry.redhat.io/openshift4/ose-cli-rhel9 +9
  • RHSA-2026:57545 Released 2026-08-25 · Red Hat rating Important
    OpenShift Container Platform 4.20.35 bug fix and security update
    • Red Hat OpenShift Container Platform 4.20 registry.redhat.io/openshift4/ose-agent-installer-ui-rhel9, registry.redhat.io/openshift4/ose-apiserver-network-proxy-rhel9, registry.redhat.io/openshift4/ose-console-rhel9 +4
Show 14 more Red Hat advisories
  • RHSA-2026:34099 Released 2026-07-09 · Red Hat rating Important
    OpenShift Container Platform 4.17.55 bug fix and security update
    • Red Hat OpenShift Container Platform 4.17 registry.redhat.io/openshift4/aws-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/azure-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/cloud-network-config-controller-rhel9 +47
  • RHSA-2026:25182 Released 2026-06-17 · Red Hat rating Important
    OpenShift Container Platform 4.18.44 bug fix and security update
    • Red Hat OpenShift Container Platform 4.18 registry.redhat.io/openshift4/azure-service-rhel9-operator, registry.redhat.io/openshift4/openshift-route-controller-manager-rhel9, registry.redhat.io/openshift4/ose-azure-file-csi-driver-rhel9 +15
  • RHSA-2026:23246 Released 2026-06-10 · Red Hat rating Important
    OpenShift Container Platform 4.19.33 bug fix and security update
    • Red Hat OpenShift Container Platform 4.19 registry.redhat.io/openshift4/aws-karpenter-provider-aws-rhel9, registry.redhat.io/openshift4/aws-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/azure-kms-encryption-provider-rhel9 +47
  • RHSA-2026:16694 Released 2026-05-13 · Red Hat rating Important
    go-toolset:rhel8 security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) delve-1.9.1-1.module+el8.8.0+16778+5fbb74f5.src::go-toolset:rhel8, delve-1.9.1-1.module+el8.8.0+16778+5fbb74f5.x86_64::go-toolset:rhel8, go-toolset-1.19.13-4.module+el8.8.0+23976+18ba1869.ppc64le::go-toolset:rhel8 +12
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) delve-1.9.1-1.module+el8.8.0+16778+5fbb74f5.src::go-toolset:rhel8, delve-1.9.1-1.module+el8.8.0+16778+5fbb74f5.x86_64::go-toolset:rhel8, go-toolset-1.19.13-4.module+el8.8.0+23976+18ba1869.src::go-toolset:rhel8 +9
  • RHSA-2026:16697 Released 2026-05-13 · Red Hat rating Important
    go-toolset:rhel8 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) delve-1.7.2-1.module+el8.6.0+12972+ebab5911.src::go-toolset:rhel8, delve-1.7.2-1.module+el8.6.0+12972+ebab5911.x86_64::go-toolset:rhel8, go-toolset-1.17.13-2.module+el8.6.0+22782+bd95fb4c.src::go-toolset:rhel8 +9
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) delve-1.7.2-1.module+el8.6.0+12972+ebab5911.src::go-toolset:rhel8, delve-1.7.2-1.module+el8.6.0+12972+ebab5911.x86_64::go-toolset:rhel8, go-toolset-1.17.13-2.module+el8.6.0+22782+bd95fb4c.aarch64::go-toolset:rhel8 +18
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) delve-1.7.2-1.module+el8.6.0+12972+ebab5911.src::go-toolset:rhel8, delve-1.7.2-1.module+el8.6.0+12972+ebab5911.x86_64::go-toolset:rhel8, go-toolset-1.17.13-2.module+el8.6.0+22782+bd95fb4c.src::go-toolset:rhel8 +9
  • RHSA-2026:16698 Released 2026-05-13 · Red Hat rating Important
    go-toolset:rhel8 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) delve-1.5.0-2.module+el8.4.0+8864+58b0fcdb.src::go-toolset:rhel8, delve-1.5.0-2.module+el8.4.0+8864+58b0fcdb.x86_64::go-toolset:rhel8, go-toolset-1.15.14-3.module+el8.4.0+22765+91da4d3f.src::go-toolset:rhel8 +9
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) delve-1.5.0-2.module+el8.4.0+8864+58b0fcdb.src::go-toolset:rhel8, delve-1.5.0-2.module+el8.4.0+8864+58b0fcdb.x86_64::go-toolset:rhel8, go-toolset-1.15.14-3.module+el8.4.0+22765+91da4d3f.src::go-toolset:rhel8 +9
  • RHSA-2026:16498 Released 2026-05-12 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) golang-1.19.13-25.el9_2, golang-bin-1.19.13-25.el9_2, golang-docs-1.19.13-25.el9_2 +4
  • RHSA-2026:16494 Released 2026-05-12 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) golang-1.17.13-12.el9_0, golang-bin-1.17.13-12.el9_0, golang-docs-1.17.13-12.el9_0 +4
  • RHSA-2026:16497 Released 2026-05-12 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) go-toolset-1.21.13-16.el9_4, golang-1.21.13-16.el9_4, golang-bin-1.21.13-16.el9_4 +4
  • RHSA-2026:16021 Released 2026-05-11 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) go-toolset-1.25.9-1.el9_6, golang-1.25.9-1.el9_6, golang-bin-1.25.9-1.el9_6 +5
  • RHSA-2026:16024 Released 2026-05-11 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) go-toolset-1.25.9-1.el10_0, golang-1.25.9-1.el10_0, golang-bin-1.25.9-1.el10_0 +5
  • RHSA-2026:10704 Released 2026-04-27 · Red Hat rating Important
    go-toolset:rhel8 security update
    • Red Hat Enterprise Linux AppStream (v. 8) delve-1.25.2-1.module+el8.10.0+23746+9db33b5e.aarch64::go-toolset:rhel8, delve-1.25.2-1.module+el8.10.0+23746+9db33b5e.ppc64le::go-toolset:rhel8, delve-1.25.2-1.module+el8.10.0+23746+9db33b5e.src::go-toolset:rhel8 +22
  • RHSA-2026:10219 Released 2026-04-24 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream (v. 9) go-toolset-1.25.9-1.el9_7, golang-1.25.9-1.el9_7, golang-bin-1.25.9-1.el9_7 +5
  • RHSA-2026:10217 Released 2026-04-23 · Red Hat rating Important
    golang security update
    • Red Hat Enterprise Linux AppStream (v. 10) go-toolset-1.25.9-3.el10_1, golang-1.25.9-3.el10_1, golang-bin-1.25.9-3.el10_1 +5

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
OpenShift Service Mesh 2Affected—
OpenShift Service Mesh 3Affected—
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Virtualization 4AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:10217
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:10704
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:10219
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:16698
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:16697
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:16697
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:16694
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:16494
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:16498
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:16024
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:16497
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:16021
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:16698
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:16697
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:16694
Red Hat OpenShift Container Platform 4.16Fixed RHSA-2026:56854
Red Hat OpenShift Container Platform 4.17Fixed RHSA-2026:34099
Red Hat OpenShift Container Platform 4.18Fixed RHSA-2026:25182
Red Hat OpenShift Container Platform 4.19Fixed RHSA-2026:23246, RHSA-2026:57408
Red Hat OpenShift Container Platform 4.20Fixed RHSA-2026:57545
Not affected: 8 products
  • OpenShift Service Mesh 2
  • OpenShift Service Mesh 3
  • Red Hat Hardened Images
  • Red Hat OpenShift Container Platform 4.16
  • Red Hat OpenShift Container Platform 4.17
  • Red Hat OpenShift Container Platform 4.18
  • Red Hat OpenShift Container Platform 4.19
  • Red Hat OpenShift Container Platform 4.20

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27140
  2. 2026-10-03 Alias added: GHSA-5w89-2c2x-6x66
  3. 2026-10-09 EPSS moved to the 50th–90th percentile

References

Advisory 1

Other 3

  • TI-2020-00578 Improper certificate validation in Microsoft Windows KEVCVSS 3.1HIGH 8.1
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2018-05208 The "go get" implementation in Go 1.9.4, when the -insecure command-line option is used… CVSS 3.1HIGH 8.8
  • TI-2018-12083 Improper input validation in [UNKNOWN] golang CVSS 3.1HIGH 8.1
  • TI-2024-16306 Mishandling of corrupt central directory record in archive/zip CVSS 3.1MEDIUM 5.5
  • TI-2021-15910 Go before 1.16.9 and 1.17.x before 1.17.2 has a Buffer Overflow via large arguments in a… CVSS 3.1CRITICAL 9.8
See all 170 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences