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TI-2026-68926 Aliases CVE-2026-106446GHSA-8r5x-fm3f-whwj

JavaScript injection in Handlebars compile via crafted AST objects

Priority HIGH 82CWE-843Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 fixed, 8 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-843 and the CVSS impact.

Summary

handlebars.js and the npm handlebars package from 4.0.0 before 4.7.10 are affected. Handlebars.compile() and Handlebars.precompile() accept pre-parsed AST objects but validate only some values, so unchecked values such as Program.blockParams.length reach generated JavaScript (CWE-94). An attacker who can supply an object instead of a template string can execute code in the server process.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 until 4.7.10, Handlebars.compile() and Handlebars.precompile() accept pre-parsed AST objects while validating only selected PathExpression, NumberLiteral, and BooleanLiteral values. This issue bypasses the AST validation introduced in version 4.7.9 for CVE-2026-33937. An attacker who can supply an object instead of a template string can place JavaScript expressions in unchecked values such as Program.blockParams.length, a non-PathExpression parameter depth, a non-string StringLiteral.value, or a non-string PathExpression.original. The compiler emits those values into generated JavaScript, causing code execution in the server process when compile output renders or wherever precompile output is loaded. Applications that pass only template strings are not affected. This issue is fixed in version 4.7.10.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00786 56th percentileScored 2026-11-07
Fix Partial handlebars.js (handlebars-lang): 4.7.10handlebars (npm): 4.7.10Red Hat: 4 advisoriesRed Hat: 4 fixed, 8 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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
handlebars-langhandlebars.js4.0.0 to before 4.7.104.7.10Patch availableCNA
—handlebars (npm)4.0.0 to before 4.7.104.7.10Patch availableGHSA-8r5x-fm3f-whwj
  • handlebars.js Vendorhandlebars-lang Affected 4.0.0 to before 4.7.10 Fixed in 4.7.10 Patch available CNA
  • handlebars (npm) Vendor— Affected 4.0.0 to before 4.7.10 Fixed in 4.7.10 Patch available GHSA-8r5x-fm3f-whwj

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:*:*:*——handlebars-lang
  • cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:*:*:* Versions — — ·handlebars-lang

Remediation

Upgrade handlebars.js and the npm handlebars package to 4.7.10. Fixed Red Hat products: Cryostat 4 (RHSA-2026:95360), Red Hat OpenShift AI 3.4 (RHSA-2026:92510), Advanced Cluster Management for Kubernetes 2.13 (RHSA-2026:92307) and multicluster engine for Kubernetes 2.8 (RHSA-2026:92303). The sources list no fixed version for Node HealthCheck Operator, Red Hat AMQ Broker 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Dev Spaces, Red Hat Quay 3, Red Hat build of Apache Camel - HawtIO 4 and Self-service automation portal 2.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA handlebars.js (handlebars-lang) Fixed in 4.7.10
  • Fix · GHSA-8r5x-fm3f-whwj handlebars (npm) Fixed in 4.7.10 Advisory →

Red Hat 4 advisories

  • RHSA-2026:95360 Released 2026-11-04 · Red Hat rating Important
    Red Hat build of Cryostat security update
    • Cryostat 4 on RHEL 9 cryostat/cryostat-grafana-dashboard-rhel9, cryostat/cryostat-openshift-console-plugin-rhel9, cryostat/cryostat-storage-rhel9
  • RHSA-2026:92510 Released 2026-10-29 · Red Hat rating Critical
    RHOAI 3.4.6 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-cli-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47
  • RHSA-2026:92307 Released 2026-10-29 · Red Hat rating Important
    Red Hat Advanced Cluster Management for Kubernetes v2.13.14 security update
    • Red Hat Advanced Cluster Management for Kubernetes 2.13 registry.redhat.io/rhacm2/acm-grafana-rhel9, registry.redhat.io/rhacm2/acm-multicluster-observability-addon-rhel9, registry.redhat.io/rhacm2/acm-prometheus-config-reloader-rhel9 +16
Show 1 more Red Hat advisories
  • RHSA-2026:92303 Released 2026-10-29 · Red Hat rating Important
    multicluster engine for Kubernetes v2.8.12 security update
    • multicluster engine for Kubernetes 2.8 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/backplane-rhel9-operator, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9 +12

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Node HealthCheck OperatorAffectedNo fix yet
Red Hat AMQ Broker 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat OpenShift Dev SpacesAffectedNo fix yet
Red Hat Quay 3AffectedNo fix yet
Red Hat build of Apache Camel - HawtIO 4AffectedNo fix yet
Self-service automation portal 2AffectedNo fix yet
Cryostat 4 on RHEL 9Fixed RHSA-2026:95360
Red Hat Advanced Cluster Management for Kubernetes 2.13Fixed RHSA-2026:92307
Red Hat OpenShift AI 3.4Fixed RHSA-2026:92510
multicluster engine for Kubernetes 2.8Fixed RHSA-2026:92303
Not affected: 18 products
  • Cryostat 4 on RHEL 9
  • Red Hat AMQ Broker 7
  • Red Hat Advanced Cluster Management for Kubernetes 2.13
  • Red Hat Data Grid 8
  • Red Hat Developer Hub 1
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux AI (RHEL AI) 3
  • Red Hat Hardened Images
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 3.4
  • Red Hat OpenShift Dev Spaces
  • Red Hat OpenShift Update Service
  • Red Hat Trusted Profile Analyzer
  • Red Hat build of Apache Camel for Spring Boot 4
  • multicluster engine for Kubernetes 2.8

Timeline

  1. 2026-10-06 Threatist record created from CVE-2026-106446
  2. 2026-10-07 CISA SSVC decision points changed
  3. 2026-10-07 Priority changed: MEDIUM → HIGH
  4. 2026-10-08 Alias added: GHSA-8r5x-fm3f-whwj
  5. 2026-10-08 Fix available: npm/[email protected] · GHSA-8r5x-fm3f-whwj
  6. 2026-10-08 CVSS score added · GHSA-8r5x-fm3f-whwj
  7. 2026-10-08 Weakness changed · GHSA-8r5x-fm3f-whwj
  8. 2026-10-08 6 new references · GHSA-8r5x-fm3f-whwj
  9. 2026-10-10 Affected versions changed · Red Hat
  10. 2026-10-10 CVSS score added · Red Hat
  11. 2026-10-15 Affected versions changed · Red Hat
  12. 2026-10-16 Affected versions changed · Red Hat
  13. 2026-10-20 Affected versions changed · Red Hat
  14. 2026-10-23 EPSS moved to the 50th–90th percentile
  15. 2026-10-27 Affected versions changed · Red Hat
  16. 2026-10-30 Fix available: RHSA-2026:92303 · Red Hat
  17. 2026-10-30 Fix available: RHSA-2026:92307 · Red Hat
  18. 2026-10-30 Fix available: RHSA-2026:92510 · Red Hat
  19. 2026-10-30 Fix available: Red Hat Advanced Cluster Management for Kubernetes 2.13, Red Hat OpenShift AI 3.4, multicluster engine for Kubernetes 2.8 · Red Hat
  20. 2026-11-05 Fix available: Cryostat 4 on RHEL 9 · Red Hat
  21. 2026-11-06 Fix available: RHSA-2026:95360 · Red Hat

References

Advisory 1

Other 5

  • TI-2026-26288 Handlebars.js has JavaScript Injection via AST Type Confusion CVSS 3.1CRITICAL 9.8
  • TI-2026-68925 JavaScript injection in Handlebars via own property check bypass CVSS 4.0CRITICAL 9.2
  • TI-2026-26290 Handlebars.js has Denial of Service via Malformed Decorator Syntax in Template Compilation CVSS 3.1HIGH 7.5
  • TI-2026-26292 Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options CVSS 3.1HIGH 8.3
  • TI-2026-26291 Handlebars.js has JavaScript Injection via AST Type Confusion when passing an object as dynamic partial CVSS 3.1HIGH 8.1
  • TI-2026-26289 Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block CVSS 3.1HIGH 8.1
See all 12 →

Sources

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