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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-118781: Forge: Denial of Service via infinite loop in BigInteger.modInverse() with negative input (incomplete fix of CVE-2026-33891)

MediumCVSS 5.3 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: digitalbazaar forge 1.4.1; azl3 python-tensorboard 2.16.2-6 on Azure Linux 3.0 Release Notes.
  • Severity is disputed: the assigning authority (CNA) scores it 2.9, NVD 5.3.

Low priority for now. Upgrade to digitalbazaar forge 1.4.1; azl3 python-tensorboard 2.16.2-6 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Oct 29, 2026
Updated
Nov 10, 2026
EPSS
0.2% · 16th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.3
CNA · GitHub_M
2.9
2.4 point gap

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-118781

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
digitalbazaarforge

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • digitalbazaar forge

    • < 1.4.1affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • digitalbazaar forgebefore 1.4.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
npmnode-forgebefore 1.4.11.4.1

Same product

digitalbazaar: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-33896Forge has a basicConstraints bypass in its certificate chain verification (RFC 5280 violation)
    36Monitor
  • CVE-2026-85393node-forge through 1.4.0 RSA PKCS#1 v1.5 Signature Forgery via Nested DigestAlgorithm Padding
    34Monitor
  • CVE-2025-66031node-forge ASN.1 Unbounded Recursion
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-118779Oct 29, 2026 · Forge: Regular expression denial of service in PEM decoding (pem.decode)
    30Monitor
  • ← EarlierCVE-2026-118780Oct 29, 2026 · Forge: verifyCertificateChain() removes trusted CA certificates with the same subject from the CA store
    14Monitor
  • Later →CVE-2026-118782Oct 29, 2026 · Forge: PKCS#12 MAC forgery and constant-key PBE via zero iteration count
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
digitalbazaar forge1.4.1 · descriptionVendor (CNA)
azl3 python-tensorboard 2.16.2-6 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
npm:node-forge1.4.1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+15 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-33891216 days apartForge has Denial of Service via Infinite Loop in BigInteger.modInverse() with Zero Input
    30Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
Low

Weakness class (CWE)

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

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. CVSS2.9 → 5.3
  2. Severitylow → medium
  3. SSVC exploitation— → none
  4. Exploit maturity— → none
  5. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records