CVE-2026-33894Public exploitNetwork attack vector

Signature forgery via noncanonical DigestInfo acceptance

Published Mar 27, 2026 · Updated Mar 27, 2026

Improper RSA signature verification in Digital Bazaar Forge before 1.4.0 allows remote attackers to forge signatures for e=3 keys. The key.verify path in lib/rsa.js accepts extra ASN.1 fields inside DigestInfo, while _decodePkcs1_v1_5 also fails to enforce eight padding bytes. Exploitation requires a low-exponent RSA key and a crafted PKCS#1 v1.5 signature, allowing attacker-controlled data to pass integrity or authenticity checks.

CVSS severity7.5
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper RSA signature verification in Digital Bazaar Forge before 1.4.0 allows remote attackers to forge signatures for e=3 keys. The key.verify path in lib/rsa.js accepts extra ASN.1 fields inside DigestInfo, while _decodePkcs1_v1_5 also fails to enforce eight padding bytes. Exploitation requires a low-exponent RSA key and a crafted PKCS#1 v1.5 signature, allowing attacker-controlled data to pass integrity or authenticity checks.

The record

CVE
CVE-2026-33894
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Digital Bazaar
Product
Forge
Classifications
CWE-347, CWE-20, T1553.002
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

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

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
CWE-20Improper Input Validation
T1553.002Subvert Trust Controls: Code Signing

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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