# CVE-2025-14505: Elliptic Cryptanalysis vulnerability when `k` has leading zeros

> Flawed ECDSA signature generation in the Elliptic library allows attackers to derive private keys and causes legitimate transaction failures.

- **Severity:** Medium 5.6 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Jan 2026
- **Updated:** 8 Jan 2026
- **Also known as:** CLSA-2026-1772583206, CLSA-2026-1789597571, DEBIAN-CVE-2025-14505, GHSA-848j-6mx2-7j84, UBUNTU-CVE-2025-14505

## What is CVE-2025-14505?

CVE-2025-14505 is a medium-severity vulnerability in Elliptic, published on 8 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ECDSA implementation of the Elliptic package generates incorrect signatures if an interim value of 'k' (as computed based on step 3.2 of  RFC 6979 https://datatracker.ietf.org/doc/html/rfc6979 ) has leading zeros and is susceptible to cryptanalysis, which can lead to secret key exposure. This happens, because the byte-length of 'k' is incorrectly computed, resulting in its getting truncated during the computation. Legitimate transactions or communications will be broken as a result. Furthermore, due to the nature of the fault, attackers could–under certain conditions–derive the secret key, if they could get their hands on both a faulty signature generated by a vulnerable version of Elliptic and a correct signature for the same inputs.

This issue affects all known versions of Elliptic (at the time of writing, versions less than or equal to 6.6.1).

Weakness: CWE-1240 (Use of a Cryptographic Primitive with a Risky Implementation)

## Which versions are affected by CVE-2025-14505?

2 open source packages ship an affected version, including elliptic.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `elliptic` | npm | All versions to 6.6.1 | None |
| `elliptic` | npm | All versions to 6.6.1 | None |

## How do I fix CVE-2025-14505?

Upgrade to a fixed version.

## Is CVE-2025-14505 being exploited?

There is no known exploitation of CVE-2025-14505 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-14505 and fix it if it is affected.

What it is: CVE-2025-14505 is a medium-severity vulnerability in Elliptic, published on 8 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-14505 in the wild and no public exploit code.

Affected packages and fixed versions:
- elliptic (npm): affected all versions up to 6.6.1; no fix listed
- elliptic (npm): affected all versions up to 6.6.1; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-14505/ (Markdown: https://insights.sbomify.com/CVE-2025-14505/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-14505
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-14505
- OSV: https://osv.dev/vulnerability/CVE-2025-14505

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-14505/
Summaries are generated and may contain mistakes; the official description above is the record.