{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-5187", "assignerOrgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "state": "PUBLISHED", "assignerShortName": "wolfSSL", "dateReserved": "2026-03-30T19:57:33.843Z", "datePublished": "2026-04-09T19:45:39.937Z", "dateUpdated": "2026-04-14T14:04:53.585Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "50d2cd11-d01a-48ed-9441-5bfce9d63b27", "shortName": "wolfSSL", "dateUpdated": "2026-04-09T19:45:39.937Z"}, "title": "Heap Out-of-Bounds Write in DecodeObjectId() in wolfSSL", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-122", "description": "CWE-122: Heap-based Buffer Overflow", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-787", "description": "CWE-787: Out-of-bounds Write", "type": "CWE"}]}], "affected": [{"vendor": "wolfSSL", "product": "wolfSSL", "modules": ["wolfcrypt/src/asn.c"], "programFiles": ["wolfcrypt/src/asn.c"], "versions": [{"status": "affected", "version": "0", "lessThanOrEqual": "5.9.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Two potential heap out-of-bounds write locations existed in DecodeObjectId() in wolfcrypt/src/asn.c. 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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "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": "2026-04-09T21:50:36.706131+00:00", "value": {"mitigation_remediation": ["Apply the latest wolfSSL patch that adds the required bounds check for two output slots and changes callers to use MAX_OID_SZ instead of sizeof(decOid).", "If the patch cannot be applied immediately, disable the WC_ASN_UNKNOWN_EXT_CB feature or avoid registering an unknown extension callback so the network\u2011reachable variant of the overflow cannot be triggered."], "summary": {"action": "Apply Patch", "impact": "Memory Corruption via Heap Out\u2011of\u2011Bounds Write"}, "threat_synthesis": {"affected_systems": "The issue resides in the wolfSSL cryptographic library; it applies to any application that links against wolfSSL versions containing the legacy DecodeObjectId implementation within wolfcrypt/src/asn.c. Specific version ranges are not enumerated in the CNA data, so all releases compiled with this code are potentially affected.", "description_and_impact": "DecodeObjectId() in wolfSSL performs an incorrect bounds check, writing two Object Identifier components into an output buffer that is only sized for one. A second flaw allows callers to pass the size of the structure instead of the intended element count, enabling an attacker to provide a crafted ASN.1 value with 33 or more arcs that overflows the buffer. The resulting heap write can corrupt adjacent memory, potentially causing crashes or unpredictable behavior; no direct remote code execution path is documented for this flaw.", "risk_and_exploitability": "The CVSS score of 2.3 indicates a low severity, and the vulnerability is not listed in CISA\u2019s KEV catalog. The exploit requires a crafted ASN.1 payload that the application processes; if the WC_ASN_UNKNOWN_EXT_CB callback is enabled, the payload could be transmitted over a network, giving a remote attacker a network\u2011reachable vector. Absent that option, exploitation remains limited to local or application\u2011level input. Overall risk is low to moderate pending the presence of the callback and the ability to supply the malicious ASN.1 data."}}}}, "created": "2026-04-10T08:38:41.999515+00:00", "updated": "2026-04-10T09:29:25.183688+00:00", "vendors": ["wolfssl", "wolfssl$PRODUCT$wolfssl"]}