{"answers":{"affected":"4 open source packages ship an affected version, including MessagePack. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-48515 in the wild and no public exploit code.","fix":"Upgrade MessagePack to a fixed version for your release line: 2.5.301 or 3.1.7.","what":"CVE-2026-48515 is a medium-severity denial of service vulnerability in MessagePack-CSharp, published on 22 Jun 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-2026-48515 and fix it if it is affected.\n\nWhat it is: CVE-2026-48515 is a medium-severity denial of service vulnerability in MessagePack-CSharp, published on 22 Jun 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-2026-48515 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- MessagePack (NuGet): affected all versions; fixed in 2.5.301\n- MessagePack (NuGet): affected all versions; fixed in 2.5.301\n- MessagePack (NuGet): affected from 3.0; fixed in 3.1.7\n- MessagePack (NuGet): affected from 3.0; fixed in 3.1.7\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-2026-48515/ (Markdown: https://insights.sbomify.com/CVE-2026-48515/index.md)","id":"CVE-2026-48515","markdown":"https://insights.sbomify.com/CVE-2026-48515/index.md","name":"CVE-2026-48515","record":{"aliases":["ECHO-6659-05ea-af1c","GHSA-cxmj-83gh-fp49"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"C# serialization library","requires_auth":"none","summary":"Attackers can cause excessive memory allocation and denial of service by sending crafted payloads with large declared dimensions to MessagePack-CSharp.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"messagepack","vendor":"messagepack"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's multi-dimensional array formatters read dimension lengths directly from the payload and allocate T[,], T[,,], or T[,,,] before validating that the dimension product matches the encoded element count. The formatter reads a guarded element array header, but allocation of the target multi-dimensional array happens before the dimensions are checked against that element count. A small payload can therefore declare large dimensions, provide an empty or tiny inner array, and cause a large heap allocation before element data is validated. This vulnerability is fixed in 2.5.301 and 3.1.7.","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-CSharp: Multi-dimensional array formatters allocate from unchecked dimensions","id":"CVE-2026-48515","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"NuGet","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":4,"n_references":1,"next":{"headline":"MessagePack-CSharp: InterfaceLookupFormatter bypasses collision-resistant comparer settings","id":"CVE-2026-48516"},"packages":[{"ecosystem":"NuGet","fixed":["2.5.301"],"introduced":["0"],"last_affected":[],"package":"MessagePack","purl":null,"source":"GHSA-cxmj-83gh-fp49"},{"ecosystem":"NuGet","fixed":["2.5.301"],"introduced":["0"],"last_affected":[],"package":"MessagePack","purl":"pkg:nuget/MessagePack","source":"GHSA-cxmj-83gh-fp49"},{"ecosystem":"NuGet","fixed":["3.1.7"],"introduced":["3.0"],"last_affected":[],"package":"MessagePack","purl":null,"source":"GHSA-cxmj-83gh-fp49"},{"ecosystem":"NuGet","fixed":["3.1.7"],"introduced":["3.0"],"last_affected":[],"package":"MessagePack","purl":"pkg:nuget/MessagePack","source":"GHSA-cxmj-83gh-fp49"}],"prev":{"headline":"MessagePack-CSharp: Unity unsafe blit formatter allocates from unbounded byte length","id":"CVE-2026-48514"},"products":["MessagePack-CSharp"],"published":"2026-06-22","related":[{"cvss_score":8.2,"headline":"MessagePack-CSharp: LZ4 decompression may fail with AccessViolationException after dereferencing memory from bad input","id":"CVE-2026-48109","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":8.2,"headline":"MessagePack-CSharp: Denial of service vulnerabilities can swamp the CPU or crash the process with stack and heap overflows","id":"CVE-2026-48502","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":7.5,"headline":"MessagePack-CSharp: MessagePackReader.Skip can recurse without enforcing maximum object graph depth","id":"CVE-2026-48506","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":6.3,"headline":"MessagePack-CSharp: ASP.NET Core MessagePackInputFormatter defaults to TrustedData for HTTP request bodies","id":"CVE-2026-48509","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":6.3,"headline":"MessagePack-CSharp: LZ4 decompression allocates from unbounded declared output lengths","id":"CVE-2026-48510","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":6.3,"headline":"MessagePack-CSharp: ExpandoObject formatter can perform quadratic insertion work on untrusted maps","id":"CVE-2026-48511","kev_date_added":null,"published":"2026-06-22"},{"cvss_score":6.3,"headline":"MessagePack-CSharp: JSON conversion APIs can recurse without consistent depth enforcement","id":"CVE-2026-48512","kev_date_added":null,"published":"2026-06-22"}],"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":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-06-25","vendors":["MessagePack-CSharp"]},"summary":"Attackers can cause excessive memory allocation and denial of service by sending crafted payloads with large declared dimensions to MessagePack-CSharp.","url":"https://insights.sbomify.com/CVE-2026-48515/"}