CVE-2026-118775 in Forge
Summary
by MITRE • 10/29/2026
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, asn1.oidToDer() in lib/asn1.js did not range-check the first two arcs of an OID. An application that accepted an untrusted OID string, checked or authorized that string, and then encoded it with asn1.oidToDer() could emit DER representing a different, trusted OID from the one that was checked. DER parsing is not affected. This issue is fixed in version 1.4.1.
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Analysis
by VulDB Data Team • 10/29/2026
The Forge library, also known as node-forge, serves as a native implementation of Transport Layer Security protocols within JavaScript environments. It provides developers with cryptographic primitives and protocol implementations necessary for securing network communications. A critical security flaw was identified in the ASN.1 handling capabilities prior to version 1.4.1, specifically within the asn1.oidToDer() function located in lib/asn1.js. This vulnerability stems from a failure to perform adequate range-checking on the first two arcs of an Object Identifier OID during encoding operations.
The technical nature of this flaw involves a logic error where input validation is insufficient before cryptographic transformation. When an application accepts an untrusted OID string, performs authorization or verification checks against that specific string value, and subsequently passes it to asn1.oidToDer() for DER encoding, the library may produce a different DER-encoded output than expected. Because the first two arcs of OIDs carry significant semantic weight in certificate structures and other X.509 related data, manipulating these values can alter the identity or properties represented by the OID without triggering the initial validation checks that relied on the original unencoded string.
This discrepancy creates a potential bypass for security controls that rely on checking OID strings before encoding them into binary formats. An attacker could potentially exploit this to inject malicious OIDs into certificate chains or other structures where DER parsing itself is not vulnerable, but the generation of those structures relies on trusted library functions. The operational impact includes the possibility of impersonating trusted entities or bypassing authorization mechanisms that depend on specific OID values being correctly represented in their encoded form.
The vulnerability aligns with CWE-20 Improper Input Validation and CWE-839 Sliver in Lock, as it involves a failure to validate input constraints before processing leading to an inconsistent state between logical checks and physical encoding. In terms of the MITRE ATT&CK framework, this behavior relates to techniques involving resource hijacking or defense evasion where valid cryptographic structures are manipulated to bypass security monitoring or access controls.
The issue has been resolved in version 1.4.1 through the implementation of proper range-checking for the first two arcs of OIDs within the asn1.js module. Developers utilizing this library should upgrade immediately to mitigate the risk of OID manipulation attacks. Additionally, applications relying on Forge for security-critical operations should ensure that all inputs are validated at multiple layers and consider implementing additional checks after encoding if strict integrity is required before transmission or storage.