CVE-2022-50237Public exploit

Private-key extraction via decoupled Keypair signing

Published Jul 28, 2025 · Updated Jul 28, 2025

Cryptographic key exposure in ed25519-dalek before 2.0.0 allows attackers to extract an Ed25519 private key through a signing oracle. The Keypair API accepts independently supplied private and public keys, so two same-message signatures made with different public keys reuse R while changing S, exposing the private scalar. Exploitation requires an application to expose signing with attacker-controlled public keys; applications that keep each keypair coupled do not expose this oracle.

CVSS severity5.9
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic key exposure in ed25519-dalek before 2.0.0 allows attackers to extract an Ed25519 private key through a signing oracle. The Keypair API accepts independently supplied private and public keys, so two same-message signatures made with different public keys reuse R while changing S, exposing the private scalar. Exploitation requires an application to expose signing with attacker-controlled public keys; applications that keep each keypair coupled do not expose this oracle.

The record

CVE
CVE-2022-50237
Published
Jul 28, 2025
Updated
Jul 28, 2025
Vendor
Dalek Cryptography
Product
ed25519-dalek
Classifications
CWE-497, T1552.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Dalek Cryptography · ed25519-dalekversion=0 <2

Published CVSS scores

5.9MITRECVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-497Exposure of Sensitive System Information to an Unauthorized Control Sphere
T1552.004Unsecured Credentials: Private Keys

Public exploit references

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Technologies

Your stack

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Your stack

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