CVE-2026-23966Network attack vector

Private-key recovery via unvalidated SM2 ciphertext points

Published Jan 22, 2026 · Updated Jan 22, 2026

Private-key recovery in JuneAndGreen sm-crypto before 0.3.14 allows remote attackers to recover SM2 private keys via crafted ciphertexts. The doDecrypt function multiplies an attacker-supplied C1 point by the private key without first verifying that the point belongs to the SM2 curve. Repeated decryption-oracle access for several hundred crafted inputs exposes the complete key, enabling decryption and forgery.

CVSS severity9.1
Critical
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Private-key recovery in JuneAndGreen sm-crypto before 0.3.14 allows remote attackers to recover SM2 private keys via crafted ciphertexts. The doDecrypt function multiplies an attacker-supplied C1 point by the private key without first verifying that the point belongs to the SM2 curve. Repeated decryption-oracle access for several hundred crafted inputs exposes the complete key, enabling decryption and forgery.

The record

CVE
CVE-2026-23966
Published
Jan 22, 2026
Updated
Jan 22, 2026
Vendor
JuneAndGreen
Product
sm-crypto
Classifications
CWE-345
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 22, 2026Record 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=< 0.3.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

JuneAndGreen · sm-cryptoversion=< 0.3.14

Published CVSS scores

9.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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