{"answers":{"affected":"4 open source packages ship an affected version, including MessagePack.","exploited":"There is no known exploitation of CVE-2026-92707 in the wild and no public exploit code.","fix":"Upgrade MessagePack to a fixed version for your release line: 2.5.303 or 3.1.9.","what":"CVE-2026-92707 is a medium-severity denial of service vulnerability in MessagePack-CSharp, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-92707 and fix it if it is affected.\n\nWhat it is: CVE-2026-92707 is a medium-severity denial of service vulnerability in MessagePack-CSharp, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-92707 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- MessagePack (NuGet): affected all versions; fixed in 2.5.303\n- MessagePack (NuGet): affected all versions; fixed in 2.5.303\n- MessagePack (NuGet): affected from 3.0.0; fixed in 3.1.9\n- MessagePack (NuGet): affected from 3.0.0; fixed in 3.1.9\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-92707/ (Markdown: https://insights.sbomify.com/CVE-2026-92707/index.md)","id":"CVE-2026-92707","markdown":"https://insights.sbomify.com/CVE-2026-92707/index.md","name":"CVE-2026-92707","record":{"aliases":["ECHO-2222-717f-2f28","GHSA-qhrr-8q5h-9q3h","UBUNTU-CVE-2026-92707"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"C# MessagePack library","requires_auth":"none","summary":"Attackers can cause denial of service via excessive memory allocation when deserializing nested arrays in MessagePack for C#.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-1325","name":"Improperly Controlled Sequential Memory Allocation"}],"description":"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.","ecosystems":["NuGet"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"MessagePack: Nested arrays can blow past buffer length limits","id":"CVE-2026-92707","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"NuGet","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":4,"n_references":5,"next":{"headline":"devalue: Cross-request process memory disclosure in devalue when `stringify` / `uneval` serialize Node Buffers","id":"CVE-2026-92708"},"packages":[{"ecosystem":"NuGet","fixed":["2.5.303"],"introduced":["0"],"last_affected":[],"package":"MessagePack","purl":null,"source":"GHSA-qhrr-8q5h-9q3h"},{"ecosystem":"NuGet","fixed":["2.5.303"],"introduced":["0"],"last_affected":[],"package":"MessagePack","purl":"pkg:nuget/MessagePack","source":"GHSA-qhrr-8q5h-9q3h"},{"ecosystem":"NuGet","fixed":["3.1.9"],"introduced":["3.0.0"],"last_affected":[],"package":"MessagePack","purl":null,"source":"GHSA-qhrr-8q5h-9q3h"},{"ecosystem":"NuGet","fixed":["3.1.9"],"introduced":["3.0.0"],"last_affected":[],"package":"MessagePack","purl":"pkg:nuget/MessagePack","source":"GHSA-qhrr-8q5h-9q3h"}],"prev":{"headline":"Dark Reader: Ability to request icon-like bitmap data from certain local web servers","id":"CVE-2026-92706"},"products":["MessagePack-CSharp"],"published":"2026-10-15","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["MessagePack-CSharp"]},"summary":"Attackers can cause denial of service via excessive memory allocation when deserializing nested arrays in MessagePack for C#.","url":"https://insights.sbomify.com/CVE-2026-92707/"}