EUVD-2026-61278
GHSA-3q3x-px7h-qhq2
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Network-reachable but requires a MITM position and a crafted chain that chains to a trusted anchor (AC:H); no auth needed (PR:N); enables impersonation/interception (C:H/I:H) but not denial of service (A:N).
Primary rating from Vendor (mitre).
CVSS VectorVendor: mitre
Lifecycle Timeline
7DescriptionCVE.org
An issue was discovered in openHiTLS 0.2.0 through 0.3.2. In the X.509 certificate chain verification, the basic constraints extension and CA flag processing of intermediate CAs are only verified for v3 certificates, and v1/v2 certificates are ignored.
AnalysisAI
Certificate chain validation bypass in the openHiTLS cryptographic library (0.2.0 through 0.3.2) lets attackers use a non-CA certificate as an intermediate CA, because basicConstraints/cA-flag checks are applied only to X.509 v3 certificates while v1/v2 intermediate certificates are silently accepted. An attacker able to obtain any leaf/end-entity certificate (or craft a v1/v2 certificate) can forge a trusted chain and impersonate arbitrary servers, enabling man-in-the-middle interception. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that the target application uses openHiTLS 0.2.0-0.3.2 to perform X.509 certificate chain verification, and that the attacker can get a victim client to validate an attacker-supplied chain - typically via a man-in-the-middle position or by luring the client to an attacker-controlled endpoint. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The vendor CVSS of 9.8 (AV:N/AC:L/PR:N/UI:N/C:H/I:H/A:H) overstates real-world ease: exploiting a certificate-validation bypass generally requires the attacker to occupy a man-in-the-middle position (or otherwise induce a victim client to validate an attacker-supplied chain), which raises attack complexity beyond the AC:L the vendor assigned, and the availability impact (A:H) is not well supported since the flaw enables impersonation/interception rather than denial of service. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Upgrade openHiTLS to version 0.3.3 or later, which contains the corrected chain-validation logic (Vendor-released patch: 0.3.3). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all internal and third-party applications using openHiTLS versions 0.2.0-0.3.2 through software inventory scans and vendor notifications, and categorize systems by business criticality. …
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Same weakness CWE-295 – Improper Certificate Validation
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External POC / Exploit Code
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