CVE-2020-36843

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.

Published: 2025-03-13 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-36843 is rated Low Risk (21.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-36843

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-14 — 0.04% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-36843

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 1.4 [email protected]

Weakness enumeration for CVE-2020-36843

GitHub Security Advisory for CVE-2020-36843

GHSA-p53j-g8pw-4w5f · Severity: medium · Ecosystem: maven — Ed25519 Signature Malleability in ed25519-java Due to Missing Scalar Range Check

OS Trackers for CVE-2020-36843

vendor priority summary link
debian not yet assigned CVE-2020-36843 not yet assigned priority: Debian including 1 source packages (libeddsa-java), 3 status rows across 3 suites (forky, sid, trixie): resolved 3. https://security-tracker.debian.org/tracker/CVE-2020-36843
suse high — https://www.suse.com/security/cve/CVE-2020-36843/
ubuntu medium CVE-2020-36843 medium priority: Ubuntu including 2 source packages (libeddsa-java, ruby-ed25519), 14 status rows across 7 suites (focal, jammy, noble, oracular, plucky, questing, upstream): needs-triage 7, ignored 4, DNE 3. https://ubuntu.com/security/CVE-2020-36843

Affected software / configurations for CVE-2020-36843

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2020-36843

cvelogic Threat Intelligence