PT-2026-28556 · Jsbn+1 · Jsbn+1

Published 2026-03-26 · Updated 2026-05-18 · CVE-2026-33891

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions node-forge versions prior to 1.4.0

Description A Denial of Service (DoS) issue exists in the node-forge library due to an infinite loop within the BigInteger.modInverse() function, inherited from the bundled jsbn library. When modInverse() is called with a zero value as input, the Extended Euclidean Algorithm enters an unreachable exit condition, causing the process to hang indefinitely and consume 100% CPU. This can occur if the application processes untrusted input that reaches the modInverse() function, potentially impacting applications utilizing DSA/ECDSA signature verification, custom RSA or Diffie-Hellman implementations, or other cryptographic protocols where an attacker can influence values passed to modInverse(). A single malicious request can cause the Node.js event loop to block, rendering the application unresponsive.

Recommendations Versions prior to 1.4.0: Upgrade to version 1.4.0 or later to resolve the issue.

Exploit

Fix

DoS

Infinite Loop

Weakness Enumeration

CWE-835

Related Identifiers

CLEANSTART-2026-BE61221

CVE-2026-33891

GHSA-5M6Q-G25R-MVWX

Affected Products

Jsbn

Node-Forge

References · 177

• 🔥 https://github.com/digitalbazaar/forge/security/advisories/GHSA-5m6q-g25r-mvwx · Exploit
• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33891.json · Exploit
• https://github.com/digitalbazaar/forge/commit/9bb8d67b99d17e4ebb5fd7596cd699e11f25d023 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-42036 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-44459 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-42035 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-6322 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-42338 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-30827 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-44455 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-69873 · Security Note
• https://osv.dev/vulnerability/CLEANSTART-2026-BE61221 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4926 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-39408 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-35213 · Security Note