CVE-2025-15444Network attack vector

Cryptographic validation bypass via incomplete subgroup check

Published Jan 6, 2026 · Updated Jan 6, 2026

Cryptographic validation bypass in Crypt::Sodium::XS before 0.000042 allows remote attackers to pass invalid Ed25519 points as valid. The bundled libsodium subgroup check in ge25519_is_on_main_subgroup multiplies a point by L but tests only X=0, omitting the required Y=Z identity condition. Exposure requires custom cryptography that passes untrusted points to core_ed25519_is_valid_point; high-level signature APIs are unaffected.

CVSS severity9.8
Critical
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic validation bypass in Crypt::Sodium::XS before 0.000042 allows remote attackers to pass invalid Ed25519 points as valid. The bundled libsodium subgroup check in ge25519_is_on_main_subgroup multiplies a point by L but tests only X=0, omitting the required Y=Z identity condition. Exposure requires custom cryptography that passes untrusted points to core_ed25519_is_valid_point; high-level signature APIs are unaffected.

The record

CVE
CVE-2025-15444
Published
Jan 6, 2026
Updated
Jan 6, 2026
Vendor
Brad Barden
Product
Crypt::Sodium::XS
Classifications
CWE-347
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 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?

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  1. Affected versionversion=0 <0.000042

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Brad Barden · Crypt::Sodium::XSversion=0 <0.000042

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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-347Improper Verification of Cryptographic Signature

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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