# CVE-2024-48948: Elliptic ECDSA signature verification bypass with leading zero bytes

Source: https://junglewise.ai/threats/cve-2024-48948-elliptic-ecdsa-signature-verification-bypass-with-leading-zero  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2024-10-15. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2024-48948 · Severity: low · CVSS 3.1 · Published 2024-10-15

Elliptic is a Node.js cryptography library used to perform ECDSA digital signature operations. A bug in its signature verification logic causes valid signatures to be incorrectly rejected when the message hash contains four or more leading zero bytes and certain curve properties are met. This can cause legitimate transactions or communications to be erroneously flagged as invalid, breaking system reliability.

Technologies: [elliptic (npm)](https://junglewise.ai/threats/technologies/elliptic). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2024-48948 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2024-48948 being exploited in the wild.

**How severe is CVE-2024-48948?** Low severity, with a CVSS score of 3.1, published 15 October 2024.

**Which products and versions are affected?** elliptic (npm) SEMVER:introduced=0,fixed=6.6.0.

**Is there a fix for CVE-2024-48948?** Yes. elliptic (npm): upgrade to 6.6.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2024-48948 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2024-48948?** Check whether you run elliptic (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- elliptic (npm): upgrade to 6.6.0 or later

  ```sh
  npm install elliptic@6.6.0
  ```


## Technical details

The vulnerability exists in the `_truncateToN` function in Elliptic prior to 6.6.0, which handles ECDSA signature verification. When the message digest is longer than the curve order, the function incorrectly truncates the hash by computing shift length based on the integer representation of the hash rather than the original digest byte length. If the digest starts with four or more leading zero bytes, this causes the function to truncate incorrectly, rejecting valid signatures that should verify successfully. The attack is triggered when processing any ECDSA signature where the hash digest size exceeds the curve order and contains leading zero bytes. The vulnerability is classified as an improper signature verification (CWE-347) and is fixed in version 6.6.0.

## Affected products

- Elliptic Elliptic before 6.6.0

## Identifiers

- CVE-2024-48948
- GHSA-fc9h-whq2-v747

## Timeline

- 2024-10-15: disclosed: Published to GitHub Advisory Database
- 2024-10-15: patched: Fixed in version 6.6.0

## References

- [https://github.com/indutny/elliptic/issues/321](https://github.com/indutny/elliptic/issues/321)

## Related threats

- [Elliptic ECDSA signature generation implementation flaw](https://junglewise.ai/threats/cve-2025-14505-elliptic-ecdsa-signature-generation-implementation-flaw)
- [Elliptic ECDSA private key extraction via malformed input](https://junglewise.ai/threats/elliptic-ecdsa-private-key-extraction-via-malformed-input-286138fe)
- [Elliptic EdDSA signature malleability via missing validation](https://junglewise.ai/threats/cve-2024-48949-elliptic-eddsa-signature-malleability-via-missing-validation)
- [Elliptic signature malleability in EDDSA and ECDSA](https://junglewise.ai/threats/cve-2024-42459-elliptic-signature-malleability-in-eddsa-and-ecdsa)
- [Elliptic ECDSA signature malleability in DER parsing](https://junglewise.ai/threats/cve-2024-42460-elliptic-ecdsa-signature-malleability-in-der-parsing)