# CVE-2026-118781: Forge: Denial of Service via infinite loop in BigInteger.modInverse() with negative input (incomplete fix of )

Source: https://junglewise.ai/threats/cve-2026-118781-forge-also-called-node-forge-is-a-native-implementation-of  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-118781 · Severity: low · CVSS 3.1 · Published 2026-10-29

Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the affected implementation used BigInteger.prototype.modInverse(), bnModInverse(), lib/jsbn.js, RSA public exponent e to process the relevant input or security decision. node-forge's bundled jsbn implementation entered an infinite loop when BigInteger.prototype.modInverse() received a negative value or modulus. An attacker who could control the RSA public exponent passed to key generation, or a direct modInverse() operand, could block the Node.js event loop at full CPU. Parsed DER, PEM, JWK, PKCS#12, X.509, and TLS values are unsigned and cannot trigger this issue. This issue is fixed in version 1.4.1.

Technologies: [node-forge (npm)](https://junglewise.ai/threats/technologies/node-forge). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-118781 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-118781 being exploited in the wild.

**How severe is CVE-2026-118781?** Low severity, with a CVSS score of 3.1, published 29 October 2026.

**Which products and versions are affected?** node-forge (npm) <= 1.4.0, SEMVER:introduced=0,fixed=1.4.1.

**Is there a fix for CVE-2026-118781?** Yes. node-forge (npm): upgrade to 1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-118781?** Check whether you run node-forge (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- node-forge (npm): upgrade to 1.4.1 or later

  ```sh
  npm install node-forge@1.4.1
  ```


## Affected products

- node-forge (npm) <= 1.4.0, SEMVER:introduced=0,fixed=1.4.1

## Identifiers

- CVE-2026-118781
- GHSA-h6cr-wjv9-3cpp

## Related threats

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- [Forge RSA PKCS#1 v1.5 signature forgery via non-canonical DigestInfo encoding](https://junglewise.ai/threats/cve-2026-119192-forge-rsa-pkcs-1-v1-5-signature-forgery-via-non-canonical)