Invoking "go bug" follows symlinks in predictable temporary filenames in cmd/go
Priority LOW 23CWE-59Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · High · None
- Fix status
- Partial Red Hat: 9 fixed, 5 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
The "go bug" command writes to two files with predictable names in the system temporary directory (for example, "/tmp"). An attacker with access to the temporary directory can create a symlink in one of these names, causing "go bug" to overwrite the target of the symlink.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00179 7th percentileScored 2026-11-07
Fix Partial cmd/go (Go toolchain): 1.25.10, 1.26.3Red Hat: 10 advisoriesRed Hat: 9 fixed, 5 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Go standard library | cmd/go | before 1.25.10; 1.26.0-0 to before 1.26.3 | 1.25.10, 1.26.3 | Patch available | CNA |
- cmd/go VendorGo standard library Affected before 1.25.10; 1.26.0-0 to before 1.26.3 Fixed in 1.25.10, 1.26.3 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* | before 1.25.10; 1.26.0 to before 1.26.3 | Vulnerable | Go standard library |
- cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* Versions before 1.25.10; 1.26.0 to before 1.26.3 Vulnerable ·Go standard library
Remediation
- Fix · CNA cmd/go (Go toolchain) Fixed in 1.25.10, 1.26.3
Red Hat 10 advisories
- RHSA-2026:66561 Released 2026-09-11 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images golang1.27-1.27.1-0.1.hum1@aarch64, golang1.27-1.27.1-0.1.hum1@src, golang1.27-1.27.1-0.1.hum1@x86_64 +10
- RHSA-2026:62391 Released 2026-09-02 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images golang1.26-1.26.8-0.1.hum1@aarch64, golang1.26-1.26.8-0.1.hum1@src, golang1.26-1.26.8-0.1.hum1@x86_64 +10
- RHSA-2026:61253 Released 2026-08-31 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) go-toolset-1.26.5-1.el9_2, golang-1.26.5-1.el9_2, golang-bin-1.26.5-1.el9_2 +5
Show 7 more Red Hat advisories
- RHSA-2026:57649 Released 2026-08-20 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) go-toolset-1.26.5-1.el9_4, golang-1.26.5-1.el9_4, golang-bin-1.26.5-1.el9_4 +5
- RHSA-2026:57194 Released 2026-08-19 · Red Hat rating Importantmulticluster engine for Kubernetes v2.11.5 security update
- multicluster engine for Kubernetes 2.11 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/backplane-rhel9-operator, registry.redhat.io/multicluster-engine/cluster-api-provider-kubevirt-rhel9 +11
- RHSA-2026:49712 Released 2026-08-03 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) go-toolset-1.26.5-1.el9_6, golang-1.26.5-1.el9_6, golang-bin-1.26.5-1.el9_6 +5
- RHSA-2026:49702 Released 2026-08-03 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) go-toolset-1.26.5-1.el10_0, golang-1.26.5-1.el10_0, golang-bin-1.26.5-1.el10_0 +5
- RHSA-2026:22112 Released 2026-06-01 · Red Hat rating Importantgo-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-2026:22121 Released 2026-06-01 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream (v. 9) go-toolset-1.26.3-1.el9_8, golang-1.26.3-1.el9_8, golang-bin-1.26.3-1.el9_8 +5
- RHSA-2026:22120 Released 2026-06-01 · Red Hat rating Importantgolang security update
- Red Hat Enterprise Linux AppStream (v. 10) go-toolset-1.26.3-4.el10_2, golang-1.26.3-4.el10_2, golang-bin-1.26.3-4.el10_2 +5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Go toolchain cmd/go 1.25.10, 1.26.3
3 records Highest priority Priority LOW 3 LOW
Other records, highest priority first
- TI-2026-30784 Malicious module proxy can bypass checksum database in cmd/goPriority LOW 34
- TI-2026-28700 Invoking "go tool pack" does not sanitize output paths in cmd/goPriority LOW 26
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Multicluster Engine for Kubernetes | Affected | — |
| OpenShift API for Data Protection | Affected | — |
| Red Hat Advanced Cluster Management for Kubernetes 2 | Affected | — |
| Red Hat Hardened Images | Affected | No fix planned: Will not fix |
| Red Hat OpenShift Container Platform 4 | Affected | — |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:22120 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:22112 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:22121 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:61253 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:57649 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:49702 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:49712 |
| Red Hat Hardened Images | Fixed | RHSA-2026:62391, RHSA-2026:66561 |
| multicluster engine for Kubernetes 2.11 | Fixed | RHSA-2026:57194 |
Not affected: 1 product
- multicluster engine for Kubernetes 2.11
Timeline
- 2026-10-02 Threatist record created from CVE-2026-39819
- 2026-10-03 Alias added: GHSA-5m4p-2gjx-p2g8
References
More Go standard library Go vulnerabilities
- 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
Sources
- CVE-2026-39819 · CVE Program
- CVE-2026-39819 · NVD
- FIRST EPSS
- GHSA-5m4p-2gjx-p2g8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-39819 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences