URLs in meta content attribute actions are not escaped in html/template
Priority LOW 27CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Partial Red Hat: 3 fixed, 8 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-79.
Summary
Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value "refresh". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow "url=" by setting htmlmetacontenturlescape=0.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00374 31st percentileScored 2026-11-07
Fix Partial html/template (Go standard library): 1.25.8, 1.26.1Red Hat: 4 advisoriesRed Hat: 3 fixed, 8 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 | html/template | before 1.25.8; 1.26.0-0 to before 1.26.1 | 1.25.8, 1.26.1 | Patch available | CNA |
- html/template VendorGo standard library Affected before 1.25.8; 1.26.0-0 to before 1.26.1 Fixed in 1.25.8, 1.26.1 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* | before 1.25.8 | Vulnerable | Go standard library |
| cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:* | 1.26.0 | Vulnerable | Go standard library |
- cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* Versions before 1.25.8 Vulnerable ·Go standard library
- cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:* Versions 1.26.0 Vulnerable ·Go standard library
Remediation
- Fix · CNA html/template (Go standard library) Fixed in 1.25.8, 1.26.1
Red Hat 4 advisories
- RHSA-2026:91249 Released 2026-10-27 · Red Hat rating CriticalRed Hat AI Base Images 3.5.5 (Neuron)
- Red Hat OpenShift AI 3.5 registry.redhat.io/rhai/base-image-neuron-rhel9
- RHSA-2026:91248 Released 2026-10-27 · Red Hat rating CriticalRed Hat AI Base Images 3.4.6 (Neuron)
- Red Hat OpenShift AI 3.4 registry.redhat.io/rhai/base-image-neuron-rhel9
- RHSA-2026:7291 Released 2026-04-09 · Red Hat rating ImportantRed 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
Show 1 more Red Hat advisories
- RHSA-2026:5192 Released 2026-03-20 · Red Hat rating ModerateRed Hat Hardened Images RPM Release
- Red Hat Hardened Images golang1.25-1.25.8-1.1.hum1@aarch64, golang1.25-1.25.8-1.1.hum1@src, golang1.25-1.25.8-1.1.hum1@x86_64 +12
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Service Mesh 2 | Affected | No fix yet: Fix deferred |
| OpenShift Service Mesh 3 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Virtualization 4 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:5192, RHSA-2026:7291 |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:91248 |
| Red Hat OpenShift AI 3.5 | Fixed | RHSA-2026:91249 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27142
- 2026-10-03 Alias added: GHSA-j4j7-vw47-rhfq
- 2026-10-30 Fix available: RHSA-2026:91248 · Red Hat
- 2026-10-30 Fix available: RHSA-2026:91249 · Red Hat
- 2026-10-30 Fix available: Red Hat OpenShift AI 3.4, Red Hat OpenShift AI 3.5 · Red Hat
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-2026-27142 · CVE Program
- CVE-2026-27142 · NVD
- FIRST EPSS
- GHSA-j4j7-vw47-rhfq · GitHub Advisory Database · CC BY 4.0
- CVE-2026-27142 · 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