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TI-2026-21593 Aliases CVE-2026-27143GHSA-cfp9-33rc-j74f

Missing bound checks can lead to memory corruption in safe Go in cmd/compile

Priority MEDIUM 50Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 27 fixed, 5 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

Arithmetic over induction variables in loops were not correctly checked for underflow or overflow. As a result, the compiler would allow for invalid indexing to occur at runtime, potentially leading to memory corruption.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00545 45th percentileScored 2026-11-07
Fix Partial cmd/compile (Go toolchain): 1.25.9, 1.26.2Red Hat: 25 advisoriesRed Hat: 27 fixed, 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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/compilebefore 1.25.9; 1.26.0-0 to before 1.26.21.25.9, 1.26.2Patch availableCNA
  • cmd/compile 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/compile (Go toolchain) Fixed in 1.25.9, 1.26.2

Red Hat 25 advisories

  • RHSA-2026:90994 Released 2026-10-27 · Red Hat rating Important
    go-toolset:rhel8 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) delve-1.26.1-1.module+el8.4.0+25181+7ce5b91c.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8, go-toolset-1.26.10-2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8 +8
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) delve-1.26.1-1.module+el8.4.0+25181+7ce5b91c.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8, go-toolset-1.26.10-2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8 +8
  • RHSA-2026:87245 Released 2026-10-21 · Red Hat rating Important
    go-toolset:rhel8 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) delve-1.26.1-1.module+el8.8.0+24781+86ad105d.ppc64le::go-toolset:rhel8, delve-1.26.1-1.module+el8.8.0+24781+86ad105d.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8 +13
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) delve-1.26.1-1.module+el8.8.0+24781+86ad105d.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8, go-toolset-1.26.10-4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8 +8
  • RHSA-2026:87246 Released 2026-10-21 · Red Hat rating Important
    go-toolset:rhel8 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) delve-1.26.1-1.module+el8.6.0+24782+a062e766.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8, go-toolset-1.26.10-4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8 +8
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) delve-1.26.1-1.module+el8.6.0+24782+a062e766.src::go-toolset:rhel8, delve-1.26.1-1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8, go-toolset-1.26.10-4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8 +8
Show 22 more Red Hat advisories
  • RHSA-2026:65840 Released 2026-09-17 · Red Hat rating Important
    OpenShift Container Platform 4.13.71 bug fix and security update
    • Red Hat OpenShift Container Platform 4.13 registry.redhat.io/openshift4/cloud-network-config-controller-rhel8, registry.redhat.io/openshift4/egress-router-cni-rhel8, registry.redhat.io/openshift4/kubevirt-csi-driver-rhel8 +47
  • RHSA-2026:59833 Released 2026-09-03 · Red Hat rating Important
    OpenShift Container Platform 4.12.97 bug fix and security update
    • Red Hat OpenShift Container Platform 4.12 registry.redhat.io/openshift4/cloud-network-config-controller-rhel8, registry.redhat.io/openshift4/egress-router-cni-rhel8, registry.redhat.io/openshift4/kubevirt-csi-driver-rhel8 +47
  • 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-2026:47712 Released 2026-07-29 · Red Hat rating Important
    golang security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) go-toolset-1.25.9-1.el9_4, golang-1.25.9-1.el9_4, golang-bin-1.25.9-1.el9_4 +4
  • RHSA-2026:47719 Released 2026-07-29 · Red Hat rating Important
    golang security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) go-toolset-1.25.9-1.el9_2, golang-1.25.9-1.el9_2, golang-bin-1.25.9-1.el9_2 +5
  • 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-2026:28964 Released 2026-07-01 · Red Hat rating Important
    OpenShift Container Platform 4.15.66 bug fix and security update
    • Red Hat OpenShift Container Platform 4.15 registry.redhat.io/openshift4/cloud-network-config-controller-rhel8, registry.redhat.io/openshift4/egress-router-cni-rhel8, registry.redhat.io/openshift4/kube-metrics-server-rhel8 +47
  • RHSA-2026:28893 Released 2026-07-01 · Red Hat rating Important
    OpenShift Container Platform 4.14.68 bug fix and security update
    • Red Hat OpenShift Container Platform 4.14 registry.redhat.io/openshift4/cloud-network-config-controller-rhel8, registry.redhat.io/openshift4/egress-router-cni-rhel8, registry.redhat.io/openshift4/kubevirt-csi-driver-rhel8 +47
  • RHSA-2026:21657 Released 2026-06-03 · Red Hat rating Important
    OpenShift Container Platform 4.18.43 bug fix and security update
    • Red Hat OpenShift Container Platform 4.18 registry.redhat.io/openshift4/aws-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/azure-kms-encryption-provider-rhel9, registry.redhat.io/openshift4/azure-service-rhel9-operator +47
  • RHSA-2026:20041 Released 2026-05-27 · Red Hat rating Important
    OpenShift Container Platform 4.19.32 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-2026:16537 Released 2026-05-12 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.3.3
    • Red Hat OpenShift Service Mesh 3.3 registry.redhat.io/openshift-service-mesh/istio-cni-rhel9, registry.redhat.io/openshift-service-mesh/istio-pilot-rhel9, registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9 +1
  • RHSA-2026:16508 Released 2026-05-12 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.2.5
    • Red Hat OpenShift Service Mesh 3.2 registry.redhat.io/openshift-service-mesh/istio-cni-rhel9, registry.redhat.io/openshift-service-mesh/istio-pilot-rhel9, registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9 +1
  • RHSA-2026:16505 Released 2026-05-12 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.1.8
    • Red Hat OpenShift Service Mesh 3.1 registry.redhat.io/openshift-service-mesh/istio-cni-rhel9, registry.redhat.io/openshift-service-mesh/istio-pilot-rhel9, registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9 +1
  • RHSA-2026:16477 Released 2026-05-12 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 3.0.11
    • Red Hat OpenShift Service Mesh 3.0 registry.redhat.io/openshift-service-mesh/istio-cni-rhel9, registry.redhat.io/openshift-service-mesh/istio-pilot-rhel9, registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9 +1
  • 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-2026:11688 Released 2026-04-29 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 2.6.15
    • Red Hat OpenShift Service Mesh 2.6 registry.redhat.io/openshift-service-mesh/istio-cni-rhel8, registry.redhat.io/openshift-service-mesh/istio-rhel8-operator, registry.redhat.io/openshift-service-mesh/pilot-rhel8 +1
  • 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
  • RHSA-2026:7385 Released 2026-04-10 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images golang1.25-1.25.9-1.hum1@aarch64, golang1.25-1.25.9-1.hum1@src, golang1.25-1.25.9-1.hum1@x86_64 +12
  • RHSA-2026:7291 Released 2026-04-09 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images golang1.26-1.26.2-1.hum1@aarch64, golang1.26-1.26.2-1.hum1@src, golang1.26-1.26.2-1.hum1@x86_64 +12

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Go toolchain cmd/compile 1.25.9, 1.26.2

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-21594 Miscompilation allows memory corruption via CONVNOP-wrapped array copy in cmd/compilePriority LOW 31
    Show all 2 records →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
OpenShift Service Mesh 2AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo 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-2026:90994
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:87246
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:87245
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:47719
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:47712
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:16024
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-2026:90994
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:87246
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:87245
Red Hat Hardened ImagesFixed RHSA-2026:7291, RHSA-2026:7385
Red Hat OpenShift Container Platform 4.12Fixed RHSA-2026:59833
Red Hat OpenShift Container Platform 4.13Fixed RHSA-2026:65840
Red Hat OpenShift Container Platform 4.14Fixed RHSA-2026:28893
Red Hat OpenShift Container Platform 4.15Fixed RHSA-2026:28964
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-2026:21657
Red Hat OpenShift Container Platform 4.19Fixed RHSA-2026:20041
Red Hat OpenShift Service Mesh 2.6Fixed RHSA-2026:11688
Red Hat OpenShift Service Mesh 3.0Fixed RHSA-2026:16477
Red Hat OpenShift Service Mesh 3.1Fixed RHSA-2026:16505
Red Hat OpenShift Service Mesh 3.2Fixed RHSA-2026:16508
Red Hat OpenShift Service Mesh 3.3Fixed RHSA-2026:16537
Not affected: 15 products
  • OpenShift Service Mesh 2
  • OpenShift Service Mesh 3
  • Red Hat OpenShift Container Platform 4.12
  • Red Hat OpenShift Container Platform 4.13
  • Red Hat OpenShift Container Platform 4.14
  • Red Hat OpenShift Container Platform 4.15
  • 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 Service Mesh 2.6
  • Red Hat OpenShift Service Mesh 3.0
  • Red Hat OpenShift Service Mesh 3.1
  • Red Hat OpenShift Service Mesh 3.2
  • Red Hat OpenShift Service Mesh 3.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27143
  2. 2026-10-03 Alias added: GHSA-cfp9-33rc-j74f
  3. 2026-10-07 EPSS moved to the 50th–90th percentile
  4. 2026-10-10 Affected versions changed · Red Hat
  5. 2026-10-22 Fix available: RHSA-2026:87245 · Red Hat
  6. 2026-10-22 Fix available: RHSA-2026:87246 · Red Hat
  7. 2026-10-23 EPSS moved to the below the 50th percentile
  8. 2026-10-23 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) +1 · Red Hat
  9. 2026-10-29 Fix available: RHSA-2026:90994 · Red Hat
  10. 2026-10-29 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · Red Hat

References

Patch 1

Advisory 1

Other 2

  • 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