CVE-2026-33894

const forge = require('node-forge'); // Simulate a vulnerable environment check console.log('Testing node-forge version for CVE-2026-33894...'); // Conceptual PoC for demonstrating the verification flaw // In a real exploit, 'sig' would be a mathematically forged blob for e=3 keys function verifySignatureWithLowExponent publicKey, message, forgedSignature) { const md = forge.md.sha1.create(); md.update(message, 'utf8'); // The vulnerable verification logic in node-forge < 1.4.0 // would accept malformed ASN.1 structures with extra garbage bytes try { const isValid = publicKey.verify(md.digest().getBytes(), forgedSignature); if (isValid) { console.log('[+] Signature verified successfully! (Vulnerable)'); } else { console.log('[-] Signature verification failed.'); } return isValid; } catch (e) { console.log('Error during verification: ' + e.message); } } // Note: Generating the actual 'forgedSignature' bytes requires // solving the cubic root equation for the specific padding structure, // which is feasible due to the low exponent (e=3) and weak padding checks.

{"cve": {"id": "CVE-2026-33894", "sourceIdentifier": "[email protected]", "published": "2026-03-27T21:17:25.983", "lastModified": "2026-04-17T21:16:42.030", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-347"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:digitalbazaar:forge:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "1.4.0", "matchCriteriaId": "824A6B69-D102-48A0-B8F2-24DEC4D749DD"}]}]}], "references": [{"url": "https://datatracker.ietf.org/doc/html/rfc2313#section-8", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/digitalbazaar/forge/security/advisories/GHSA-ppp5-5v6c-4jwp", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://github.com/digitalbazaar/forge/security/advisories/GHSA-ppp5-5v6c-4jwp", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://mailarchive.ietf.org/arch/msg/openpgp/5rnE9ZRN1AokBVj3VqblGlP63QE", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://www.rfc-editor.org/rfc/rfc8017.html", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}