# CVE-2026-2739: This affects versions of the package bn.js before 5.2.3. Calling maskn(0) on any BN instance corrupts the internal state, causing toString(), divmod(), and other methods to enter an infinite loop, hanging the process indefinitely.

CVE-2026-2739 is fixed in node-bn.js on 1 platform by DEBIAN-CVE-2026-2739 (version 5.2.3+~5.2.0-1), released February 20, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-2739
- Priority: Routine
- CVSS: n/a (Moderate)
- EPSS: 0.0053
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 20, 2026
- Weakness: Loop with Unreachable Exit Condition ('Infinite Loop')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-2739

## Description

This affects versions of the package bn.js before 5.2.3. Calling maskn(0) on any BN instance corrupts the internal state, causing toString(), divmod(), and other methods to enter an infinite loop, hanging the process indefinitely.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-bn.js Debian 14 | 5.2.3+~5.2.0-1 | [DEBIAN-CVE-2026-2739](https://patchblox.com/security/data/fix/linux/debian-cve-2026-2739.md) | Feb 20, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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