01 Record

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,

MediumPUBLISHEDCNA: snyk

CNA base score6.9 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

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02 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,

03 Exploitation and scoring

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.53% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 44.5% of scored records. A rank, not a probability.

NVD base score

5.5 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2026-02-20 05:00Z8 MO AGO

Last updated

2026-02-20 15:03Z8 MO AGO

Reserved

2026-02-19

Assigning CNA

snyk

Record state

PUBLISHED

Severity

Medium (CVSS 6.9)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Weaknesses

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')Base

Data version

5.2

Document digest

1d803bf3f9307374c1fada7549dbe2b56d1bbe9bdf20e1fd91dfdb7743cda349

05 Affected products

VendorProductVersionsPlatforms

n/abn.js0 to < 5.2.3—

06 References

security.snyk.iohttps://security.snyk.io/vuln/SNYK-JS-BNJS-15274301
github.comhttps://github.com/indutny/bn.js/issues/316
github.comhttps://github.com/indutny/bn.js/issues/186
gist.github.comhttps://gist.github.com/Kr0emer/02370d18328c28b5dd7f9ac880d22a91
github.comhttps://github.com/indutny/bn.js/pull/317
github.comhttps://github.com/indutny/bn.js/commit/33df26b5771e824f303a79ec6407409376baa64b

07 Fixed in

Debian 12

node-bn.js
No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

node-bn.js
No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

node-bn.js
Fixed in 5.2.3+~5.2.0-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.