Forge has Denial of Service via Infinite Loop in BigInteger.modInverse() with Zero Input
Priority HIGH 72CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 7 fixed, 5 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-835.
Summary
Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, a Denial of Service (DoS) vulnerability exists in the node-forge library due to an infinite loop in the BigInteger.modInverse() function (inherited from the bundled jsbn library). When modInverse() is called with a zero value as input, the internal Extended Euclidean Algorithm enters an unreachable exit condition, causing the process to hang indefinitely and consume 100% CPU. Version 1.4.0 patches the issue.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00607 49th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial forge (digitalbazaar): 1.4.0node-forge (npm): 1.4.0Red Hat: 6 advisoriesRed Hat: 7 fixed, 5 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- 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 |
|---|---|---|---|---|---|
| digitalbazaar | forge | before 1.4.0 | 1.4.0 | Patch available | CNA |
| — | node-forge (npm) | before 1.4.0 | 1.4.0 | Patch available | GHSA-5m6q-g25r-mvwx |
- forge Vendordigitalbazaar Affected before 1.4.0 Fixed in 1.4.0 Patch available CNA
- node-forge (npm) Vendor— Affected before 1.4.0 Fixed in 1.4.0 Patch available GHSA-5m6q-g25r-mvwx
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:digitalbazaar:forge:*:*:*:*:*:node.js:*:* | up to 1.3.3 | Vulnerable | digitalbazaar |
- cpe:2.3:a:digitalbazaar:forge:*:*:*:*:*:node.js:*:* Versions up to 1.3.3 Vulnerable ·digitalbazaar
Remediation
- Fix · CNA forge (digitalbazaar) Fixed in 1.4.0
- Fix · GHSA-5m6q-g25r-mvwx node-forge (npm) Fixed in 1.4.0 Advisory →
Red Hat 6 advisories
- RHSA-2026:86618 Released 2026-10-21 · Red Hat rating CriticalNew container image: rhceph-9.2
- Red Hat Ceph Storage 9.2 registry.redhat.io/rhceph/rhceph-9-rhel10
- RHSA-2026:34342 Released 2026-07-01 · Red Hat rating CriticalCluster Observability Operator 1.5.0
- Cluster Observability Operator 1.5 registry.redhat.io/cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9, registry.redhat.io/cluster-observability-operator/distributed-tracing-console-plugin-pf5-rhel9, registry.redhat.io/cluster-observability-operator/distributed-tracing-console-plugin-pf6-rhel9 +9
- RHSA-2026:24761 Released 2026-06-09 · Red Hat rating ImportantRed Hat Ansible Automation Platform 2.5 Product Security and Bug Fix Update
- Red Hat Ansible Automation Platform 2.5 for RHEL 8 automation-controller-venv-tower-4.6.29-2.el8ap, automation-gateway-proxy-server-2.5.10-6.el8ap, automation-gateway-server-2.5.20260422-3.el8ap +4
- Red Hat Ansible Automation Platform 2.5 for RHEL 9 automation-controller-venv-tower-4.6.29-2.el9ap, automation-gateway-proxy-server-2.6.14-3.el9ap, automation-gateway-server-2.5.20260422-3.el9ap +4
Show 3 more Red Hat advisories
- RHSA-2026:24762 Released 2026-06-09 · Red Hat rating ImportantRed Hat Ansible Automation Platform 2.6 Product Security and Bug Fix Update
- Red Hat Ansible Automation Platform 2.6 for RHEL 10 python3-click-8.3.3-1.el10ap, receptor-1.6.5-1.el10ap, receptorctl-1.6.5-1.el10ap
- Red Hat Ansible Automation Platform 2.6 for RHEL 9 automation-controller-4.7.12-1.el9ap, automation-controller-cli-4.7.12-1.el9ap, automation-controller-server-4.7.12-1.el9ap +10
- RHSA-2026:13826 Released 2026-05-05 · Red Hat rating CriticalRed Hat Developer Hub 1.9.4 release.
- Red Hat Developer Hub 1.9 registry.redhat.io/rhdh/rhdh-hub-rhel9, registry.redhat.io/rhdh/rhdh-rhel9-operator
- RHSA-2026:9742 Released 2026-04-22 · Red Hat rating CriticalRed Hat Developer Hub 1.8.6 release.
- Red Hat Developer Hub 1.8 registry.redhat.io/rhdh/rhdh-hub-rhel9, registry.redhat.io/rhdh/rhdh-rhel9-operator
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Logging Subsystem for Red Hat OpenShift | Affected | No fix planned: Will not fix |
| Red Hat Build of Podman Desktop | Affected | No fix yet |
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Fuse 7 | Affected | No fix planned: Will not fix |
| Red Hat build of Apicurio Registry 2 | Affected | No fix yet |
| Cluster Observability Operator 1.5 | Fixed | RHSA-2026:34342 |
| Red Hat Ansible Automation Platform 2.5 for RHEL 8 | Fixed | RHSA-2026:24761 |
| Red Hat Ansible Automation Platform 2.5 for RHEL 9 | Fixed | RHSA-2026:24761 |
| Red Hat Ansible Automation Platform 2.6 for RHEL 9 | Fixed | RHSA-2026:24762 |
| Red Hat Ceph Storage 9.2 | Fixed | RHSA-2026:86618 |
| Red Hat Developer Hub 1.8 | Fixed | RHSA-2026:9742 |
| Red Hat Developer Hub 1.9 | Fixed | RHSA-2026:13826 |
Not affected: 16 products
- Cluster Observability Operator 1.5
- Cryostat 4
- Red Hat Ansible Automation Platform 2
- Red Hat Ansible Automation Platform 2.5 for RHEL 8
- Red Hat Ansible Automation Platform 2.5 for RHEL 9
- Red Hat Ansible Automation Platform 2.6 for RHEL 10
- Red Hat Ansible Automation Platform 2.6 for RHEL 9
- Red Hat Ceph Storage 9.2
- Red Hat Data Grid 8
- Red Hat Developer Hub 1.8
- Red Hat Developer Hub 1.9
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Process Automation 7
- Red Hat Quay 3
- Red Hat build of Apache Camel - HawtIO 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-33891
- 2026-10-03 Alias added: GHSA-5m6q-g25r-mvwx
- 2026-10-21 Fix available: RHSA-2026:86618 · Red Hat
- 2026-10-21 Fix available: Red Hat Ceph Storage 9.2 · Red Hat
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-11-05 Fix available: Cluster Observability Operator 1.5 · Red Hat
References
More digitalbazaar Forge vulnerabilities
- TI-2026-26254 Forge has a basicConstraints bypass in its certificate chain verification (RFC 5280 violation) CVSS 3.1CRITICAL 9.1
- TI-2026-82739 ASN.1 resource exhaustion in Forge asn1.fromDer via BIT STRINGs CVSS 3.1HIGH 7.5
- TI-2026-82735 Denial of service in Forge TLS record processing via stack exhaustion CVSS 3.1HIGH 7.5
- TI-2026-26253 Forge has signature forgery in Ed25519 due to missing S > L check CVSS 3.1HIGH 7.5
- TI-2026-26252 Forge has signature forgery in RSA-PKCS due to ASN.1 extra field CVSS 3.1HIGH 7.5
- TI-2026-82723 Incomplete PKCS#7 padding validation in Forge decryption CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-33891 · CVE Program
- CVE-2026-33891 · NVD
- FIRST EPSS
- GHSA-5m6q-g25r-mvwx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-33891 · 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