CVE-2026-5501

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{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,5.9.0]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "wolfSSL", "source": "cna", "vendor": "wolfSSL"}, "product": "wolfssl", "vendor": "wolfssl"}], "analysis": {"en": {"generated_at": "2026-04-10T04:21:22.381345+00:00", "value": {"mitigation_remediation": ["Update wolfSSL to the latest release that incorporates the fix for the OpenSSL compatibility path.", "Verify that the application is using the native wolfSSL TLS handshake path instead of the OpenSSL compatibility API.", "If upgrading is not immediately possible, restrict inbound TLS traffic to known, trusted clients or servers to mitigate the risk of accepting forged certificates."], "summary": {"action": "Immediate Patch", "impact": "Certificate Spoofing"}, "threat_synthesis": {"affected_systems": "The vulnerability affects the wolfSSL library itself, specifically versions that expose the OpenSSL compatibility API. Applications that integrate wolfSSL via this API\u2014such as nginx and haproxy\u2014are susceptible. No specific product version details are provided in the input.", "description_and_impact": "A flaw in the wolfSSL OpenSSL compatibility layer allows a certificate chain to be accepted when the leaf certificate's signature is not verified. When an application supplies an untrusted intermediate with the Basic Constraints field set to CA:FALSE that is still legitimately signed by a trusted root, the verification function returns success even though the leaf was not properly checked. As a result an attacker who can obtain any leaf certificate from a public CA, for example a free DV certificate from Let\u2019s Encrypt, can create a forged certificate for any subject and public key. The function then reports success, enabling the attacker to impersonate a legitimate server or client and potentially carry out man\u2011in\u2011the\u2011middle attacks, credential theft, or data exfiltration. Only the OpenSSL compatibility API is affected; the native wolfSSL TLS handshake path remains secure.", "risk_and_exploitability": "The CVSS score of 8.6 indicates a high severity. EPSS data is unavailable and the issue is not listed in the CISA KEV catalog, suggesting limited observed exploitation. The likely attack vector involves an attacker delivering a crafted certificate chain to an application using the affected API, exploiting the missing leaf signature check to establish a TLS session with the attacker\u2019s forged credentials. Because the flaw operates without interacting with the application\u2019s native certificate verification path, it can be triggered remotely by simply presenting the forged chain during the TLS handshake."}}}}, "created": "2026-04-10T08:35:54.564021+00:00", "updated": "2026-04-10T09:26:56.268657+00:00", "vendors": ["wolfssl", "wolfssl$PRODUCT$wolfssl"]}