{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-54431", "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "state": "PUBLISHED", "assignerShortName": "CERT-PL", "dateReserved": "2026-06-15T13:08:01.057Z", "datePublished": "2026-07-02T10:30:57.655Z", "dateUpdated": "2026-07-02T12:16:41.569Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "shortName": "CERT-PL", "dateUpdated": "2026-07-02T10:44:44.691Z"}, "title": "Improper Data Validation in liboauth2", "datePublic": "2026-07-02T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-358", "description": "CWE-358 Improperly Implemented Security Check for Standard", "type": "CWE"}]}], "affected": [{"vendor": "OpenIDC", "product": "liboauth2", "repo": "https://github.com/OpenIDC/liboauth2", "programFiles": ["src/dpop.c"], "programRoutines": [{"name": "_oauth2_dpop_parse_and_validate()"}], "versions": [{"status": "affected", "version": "0", "lessThan": "2.3.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key\u00a0material. RFC 9449 section 4.3 step 7 requires the verifier to reject\u00a0such a proof but\u00a0oauth2_token_verify() function returns success for a malformed DPoP\u00a0proof that embeds the private Elliptic Curve (EC) key in the header.\n\nThis issue was fixed in version 2.3.0", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<span>In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key&nbsp;</span><span>material. RFC 9449 section 4.3 step 7 requires the verifier to reject&nbsp;</span><span>such a proof but</span><span>&nbsp;<i>oauth2_token_verify()</i> function returns success for a malformed DPoP&nbsp;</span><span>proof that embeds the private Elliptic Curve (EC) key in the header.<br><br></span>This issue was fixed in version 2.3.0"}]}], "tags": ["x_open-source"], "references": [{"url": "https://cert.pl/en/posts/2026/07/CVE-2026-54430", "tags": ["third-party-advisory"]}, {"url": "https://github.com/OpenIDC/liboauth2", "tags": ["product"]}, {"url": "https://github.com/OpenIDC/liboauth2/commit/c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800", "tags": ["issue-tracking"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "MEDIUM", "baseScore": 5.1, "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"}}], "credits": [{"lang": "en", "value": "Micha\u0142 Majchrowicz (AFINE Team)", "type": "finder"}, {"lang": "en", "value": "Marcin Wyczechowski (AFINE Team)", "type": "finder"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 0.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-07-02T12:16:34.432412Z", "id": "CVE-2026-54431", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-02T12:16:41.569Z"}}]}}

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