CVE-2026-92707

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{"affected": [{"affectedData": [{"product": "MessagePack-CSharp", "vendor": "MessagePack-CSharp", "versions": [{"status": "affected", "version": "< 2.5.303"}, {"status": "affected", "version": ">= 3.0.0, < 3.1.9"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.303 and 3.1.9, deserializing attacker-controlled MessagePack data as System.Object through PrimitiveObjectFormatter can cause excessive memory allocation. The formatter allocates an object[] from each declared array length before the configured object-graph depth limit rejects the input, while nested array headers can reuse the same trailing unread bytes to satisfy per-header length validation. A comparatively small payload can therefore keep many large arrays alive at once. When an attacker can submit such data repeatedly, the allocations can cause severe managed-heap pressure, excessive garbage collection, process termination, or loss of service. Exposure requires an application to deserialize untrusted data through the affected formatter path and permit repeated attacker-controlled submissions, such as a reachable ASP.NET Core SignalR hub method with an object parameter and AddMessagePackProtocol() enabled. This issue is fixed in versions 2.5.303 and 3.1.9."}], "id": "CVE-2026-92707", "lastModified": "2026-10-16T16:00:33.533", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-92707", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-15T20:10:28.719217Z", "version": "2.0.3"}}]}, "published": "2026-10-15T19:17:48.703", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/commit/7fd78bbf3476e03beae8b0f7a521125525a8a64a"}, {"source": "security-advisories@github.com", "url": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/commit/95b63fca4f7097d3cac12d1a95286af4b4bbf02c"}, {"source": "security-advisories@github.com", "url": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/releases/tag/v2.5.303"}, {"source": "security-advisories@github.com", "url": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/releases/tag/v3.1.9"}, {"source": "security-advisories@github.com", "url": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-qhrr-8q5h-9q3h"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1325"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "dotnet10.0: dotnet8.0: dotnet9.0: dotnet: MessagePack: Nested arrays can blow past buffer length limits", "id": "2548800", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2548800"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "status": "draft"}, "details": ["MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.303 and 3.1.9, deserializing attacker-controlled MessagePack data as System.Object through PrimitiveObjectFormatter can cause excessive memory allocation. The formatter allocates an object[] from each declared array length before the configured object-graph depth limit rejects the input, while nested array headers can reuse the same trailing unread bytes to satisfy per-header length validation. A comparatively small payload can therefore keep many large arrays alive at once. When an attacker can submit such data repeatedly, the allocations can cause severe managed-heap pressure, excessive garbage collection, process termination, or loss of service. Exposure requires an application to deserialize untrusted data through the affected formatter path and permit repeated attacker-controlled submissions, such as a reachable ASP.NET Core SignalR hub method with an object parameter and AddMessagePackProtocol() enabled. This issue is fixed in versions 2.5.303 and 3.1.9.", "MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.303 and 3.1.9, deserializing attacker-controlled MessagePack data as System.Object through PrimitiveObjectFormatter can cause excessive memory allocation. The formatter allocates an object[] from each declared array length before the configured object-graph depth limit rejects the input, while nested array headers can reuse the same trailing unread bytes to satisfy per-header length validation. A comparatively small payload can therefore keep many large arrays alive at once. When an attacker can submit such data repeatedly, the allocations can cause severe managed-heap pressure, excessive garbage collection, process termination, or loss of service. Exposure requires an application to deserialize untrusted data through the affected formatter path and permit repeated attacker-controlled submissions, such as a reachable ASP.NET Core SignalR hub method with an object parameter and AddMessagePackProtocol() enabled. This issue is fixed in versions 2.5.303 and 3.1.9."], "name": "CVE-2026-92707", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "dotnet10.0", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "dotnet8.0", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "dotnet9.0", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "dotnet10.0", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "dotnet8.0", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "dotnet9.0", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "dotnet10.0", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "dotnet8.0", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "dotnet9.0", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "dotnet10.0", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "dotnet8.0", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "dotnet9.0", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-10-13T17:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-92707\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-92707"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.5.303)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.0.0,3.1.9)"}}], "enrichment": {"confidence": 90.0, "confidence_source": "matching", "scores": [{"score": 90.0, "source": "matching"}]}, "original": {"product": "MessagePack-CSharp", "source": "cna", "vendor": "MessagePack-CSharp"}, "product": "messagepack-csharp", "vendor": "messagepack"}], "created": "2026-10-16T17:45:14.080513+00:00", "updated": "2026-10-19T14:01:03.797889+00:00", "vendors": ["messagepack", "messagepack$PRODUCT$messagepack-csharp"]}