forge: Loop with Unreachable Exit Condition
CVE-2026-33891 is a high-severity loop with unreachable exit condition vulnerability in forge from Digitalbazaar, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected forge versions: < 1.4.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of forge you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Digitalbazaar | forge | < 1.4.0 | Not stated |
| Red Hat | Red Hat Ansible Automation Platform 2.5 for RHEL 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Ansible Automation Platform 2.5 for RHEL 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Ansible Automation Platform 2.6 for RHEL 9 | Not specified in the record | Not stated |
| Red Hat | Cluster Observability Operator 1.5.0 | Not specified in the record | Not stated |
| Red Hat | Red Hat Developer Hub 1.8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Developer Hub 1.9 | Not specified in the record | Not stated |
| Red Hat | Cryostat 4 | Not specified in the record | Not stated |
| Red Hat | Logging Subsystem for Red Hat OpenShift | Not specified in the record | Not stated |
| Red Hat | Red Hat Ansible Automation Platform 2 | Not specified in the record | Not stated |
| Red Hat | Red Hat build of Apache Camel - HawtIO 4 | Not specified in the record | Not stated |
| Red Hat | Red Hat build of Apicurio Registry 2 | Not specified in the record | Not stated |
| Red Hat | Red Hat Build of Podman Desktop | Not specified in the record | Not stated |
| Red Hat | Red Hat Data Grid 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Fuse 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Process Automation 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Quay 3 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | CNA |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Loop with Unreachable Exit Condition
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
More Loop with Unreachable Exit Condition vulnerabilities (CWE-835)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
- access.redhat.com/errata/RHSA-2026:13826
- access.redhat.com/errata/RHSA-2026:24761
- access.redhat.com/errata/RHSA-2026:24762
- access.redhat.com/errata/RHSA-2026:34342
- access.redhat.com/errata/RHSA-2026:9742
- access.redhat.com/security/cve/CVE-2026-33891
- bugzilla.redhat.com/show_bug.cgi?id=2452450
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33891.json
Other vulnerabilities in forge
- 7.4 High severity
- 7.5 High severity
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Loop with Unreachable Exit Condition vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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