CVE-2026-33895Public exploitNetwork attack vector

Authentication bypass via non-canonical Ed25519 signatures

Published Mar 27, 2026 · Updated Mar 27, 2026

Improper Ed25519 signature verification in Digital Bazaar Forge before 1.4.0 allows remote attackers to bypass signature-based controls. The crypto_sign_open function in lib/ed25519.js passes the signature's S bytes directly to scalar multiplication without rejecting values at or above the group order L. Applications that rely on unique signature bytes for authentication, authorization, replay tracking, deduplication, or canonicalization accept an S + L variant of a valid signature.

CVSS severity7.5
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper Ed25519 signature verification in Digital Bazaar Forge before 1.4.0 allows remote attackers to bypass signature-based controls. The crypto_sign_open function in lib/ed25519.js passes the signature's S bytes directly to scalar multiplication without rejecting values at or above the group order L. Applications that rely on unique signature bytes for authentication, authorization, replay tracking, deduplication, or canonicalization accept an S + L variant of a valid signature.

The record

CVE
CVE-2026-33895
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Digital Bazaar
Product
Forge
Classifications
CWE-20, CWE-347
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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=< 1.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Digital Bazaar · Forgeversion=< 1.4.0

Published CVSS scores

7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-347Improper Verification of Cryptographic Signature

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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