Vulnerability · Published Mar 13, 2025 · Assigned by mitre
CVE-2020-36843
Medium 4.3
In plain English
A medium-severity security flaw in ed25519-java from str4d. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The implementation of EdDSA in EdDSA-Java (aka ed25519-java) through 0.3.0 exhibits signature malleability and does not satisfy the SUF-CMA (Strong Existential Unforgeability under Chosen Message Attacks) property. This allows attackers to create new valid signatures different from previous signatures for a known message.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | libeddsa-java | 0.3.0-2.1 | DEBIAN-CVE-2020-36843 |
| Debian:14 | libeddsa-java | 0.3.0-2.1 | DEBIAN-CVE-2020-36843 |
| Maven | net.i2p.crypto:eddsa | no fix listed | GHSA-p53j-g8pw-4w5f |
| Maven | net.i2p:i2p | 0.9.39 | GHSA-p53j-g8pw-4w5f |
| Ubuntu:25.10 | libeddsa-java | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:26.04:LTS | libeddsa-java | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:26.10 | libeddsa-java | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:22.04:LTS | ruby-ed25519 | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:24.04:LTS | ruby-ed25519 | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:25.10 | ruby-ed25519 | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:26.04:LTS | ruby-ed25519 | no fix listed | UBUNTU-CVE-2020-36843 |
| Ubuntu:26.10 | ruby-ed25519 | no fix listed | UBUNTU-CVE-2020-36843 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| str4d | ed25519-java | 0 – through 0.3.0 |
Weakness: CWE-347 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N