Improper signature verification in str4d ed25519-java
Priority LOW 19CWE-347Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00143 3rd percentileScored 2026-11-07
Fix Fixed net.i2p:i2p (Maven): 0.9.39
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| str4d | ed25519-java | up to 0.3.0 | — | No fix listed | CNA |
| — | net.i2p.crypto:eddsa (Maven) | up to 0.3.0 | — | No fix listed | GHSA-p53j-g8pw-4w5f |
| — | net.i2p:i2p (Maven) | before 0.9.39 | 0.9.39 | Patch available | GHSA-p53j-g8pw-4w5f |
- ed25519-java Vendorstr4d Affected up to 0.3.0 Fixed in — No fix listed CNA
- net.i2p.crypto:eddsa (Maven) Vendor— Affected up to 0.3.0 Fixed in — No fix listed GHSA-p53j-g8pw-4w5f
- net.i2p:i2p (Maven) Vendor— Affected before 0.9.39 Fixed in 0.9.39 Patch available GHSA-p53j-g8pw-4w5f
Remediation
- Fix · GHSA-p53j-g8pw-4w5f net.i2p:i2p (Maven) Fixed in 0.9.39 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2020-36843
- 2026-10-03 Alias added: GHSA-p53j-g8pw-4w5f
References
Sources
- CVE-2020-36843 · CVE Program
- CVE-2020-36843 · NVD
- FIRST EPSS
- GHSA-p53j-g8pw-4w5f · GitHub Advisory Database · CC BY 4.0
- CVE-2020-36843 · Red Hat security data · CC BY 4.0
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