CVE-2026-33894

High

Published: 27 March 2026

Published

27 March 2026

Modified

17 April 2026

KEV Added

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Patch

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CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Score 0.0004 13.6th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-33894 is a high-severity Improper Input Validation (CWE-20) vulnerability in Digitalbazaar Forge. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 RA-5 (Vulnerability Monitoring and Scanning) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

preventrecover

Directly mandates timely identification, reporting, and correction of flaws like the RSASSA PKCS#1 v1.5 signature verification vulnerability by upgrading node-forge to version 1.4.0.

RA-5 Vulnerability Monitoring and Scanning good match

detect

Requires vulnerability monitoring and scanning to identify known issues such as CVE-2026-33894 in JavaScript dependencies like node-forge.

SI-10 Information Input Validation partial match

prevent

Addresses the improper input validation (CWE-20) in signature ASN structure and padding by requiring validation checks at system entry points, supplementing flawed library behavior.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1553.002 Code Signing Defense Impairment

Adversaries may create, acquire, or steal code signing materials to sign their malware or tools.

attack.mitre.org →

Why these techniques?

Remote unauthenticated signature forgery vuln in public-facing TLS/crypto library directly enables initial access via public app exploitation (T1190) and bypass of cryptographic signature verification (T1553.002).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, RSASSA PKCS#1 v1.5 signature verification accepts forged signatures for low public exponent keys (e=3). Attackers can forge signatures by stuffing “garbage” bytes…

within the ASN structure in order to construct a signature that passes verification, enabling Bleichenbacher style forgery. This issue is similar to CVE-2022-24771, but adds bytes in an addition field within the ASN structure, rather than outside of it. Additionally, forge does not validate that signatures include a minimum of 8 bytes of padding as defined by the specification, providing attackers additional space to construct Bleichenbacher forgeries. Version 1.4.0 patches the issue.

Deeper analysisAI

CVE-2026-33894 affects Forge, also known as node-forge, a JavaScript implementation of Transport Layer Security (TLS). Prior to version 1.4.0, the library's RSASSA PKCS#1 v1.5 signature verification is vulnerable to forgery for keys with low public exponents (e=3). Attackers can craft invalid signatures that pass verification by inserting "garbage" bytes within the ASN structure, enabling Bleichenbacher-style attacks. This flaw differs from the similar CVE-2022-24771 by placing bytes in an additional field inside the ASN structure rather than outside it. Additionally, Forge fails to enforce the specification's requirement for at least 8 bytes of padding in signatures, giving attackers more room to construct forgeries. The vulnerability is rated 7.5 on the CVSS 3.1 scale (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N) and maps to CWE-20 (Improper Input Validation) and CWE-347 (Improper Verification of Cryptographic Signature).

Remote attackers require no privileges or user interaction to exploit this over the network with low complexity. Successful exploitation allows forging signatures that the library accepts as valid, potentially enabling attackers to impersonate legitimate signers, bypass authentication mechanisms, or tamper with signed data in applications relying on Forge for TLS or cryptographic operations.

The GitHub security advisory (GHSA-ppp5-5v6c-4jwp) confirms that version 1.4.0 fully patches the issue by addressing the ASN structure handling and padding validation deficiencies. Security practitioners should upgrade affected Forge installations to 1.4.0 or later and audit dependencies in JavaScript applications using this library for signature verification.