{"schemaVersion":3,"id":"CVE-2026-40891","aliases":["CGA-527j-j3c2-c39g","CGA-w3m2-wc4m-p6rj","GHSA-mr8r-92fq-pj8p","CGA-x8f8-5ggj-cc89"],"status":"published","duplicateOf":null,"title":null,"description":"OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry over gRPC using the OpenTelemetry Protocol (OTLP), the exporter may parse a server-provided grpc-status-details-bin trailer during retry handling. Prior to the fix, a malformed trailer could encode an extremely large length-delimited protobuf field which was used directly for allocation, allowing excessive memory allocation and potential denial of service (DoS). This vulnerability is fixed in 1.15.2.","dates":{"published":"2026-04-23T17:54:36.033Z","modified":"2026-04-23T18:23:08.858Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":5.3,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":5.3,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Wolfi","score":5.3,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":4.1,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Chainguard","score":5.3,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":4.1,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Nuget","score":5.3,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":4.1,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":5.3,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00287,"percentile":0.19966,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0.09500000000000001,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.00192},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00287,"percentile":0.19966}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00192,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00287,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00287,"percentile":0.19966}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-789","name":"Memory Allocation with Excessive Size Value","description":"The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.","type":"weakness","status":"Draft","abstraction":"Variant","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/789.html"}],"affected":[{"vendor":"chainguard","product":"azure-functions-host","name":"azure-functions-host","label":"azure-functions-host","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/azure-functions-host","purlType":"apk","versions":[{"text":"< 4.1051.100-r0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 4.1051.100-r0","eol":null,"hubHref":null},{"vendor":"chainguard","product":"kubernetes-reflector","name":"kubernetes-reflector","label":"kubernetes-reflector","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/kubernetes-reflector","purlType":"apk","versions":[{"text":"< 10.0.39-r1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 10.0.39-r1","eol":null,"hubHref":null},{"vendor":"wolfi","product":"kubernetes-reflector","name":"kubernetes-reflector","label":"kubernetes-reflector","ecosystem":"Wolfi","cpePart":null,"purl":"pkg:apk/wolfi/kubernetes-reflector","purlType":"apk","versions":[{"text":"< 10.0.39-r1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 10.0.39-r1","eol":null,"hubHref":null},{"vendor":"NuGet","product":"OpenTelemetry.Exporter.OpenTelemetryProtocol","name":"OpenTelemetry.Exporter.OpenTelemetryProtocol","label":"OpenTelemetry.Exporter.OpenTelemetryProtocol","ecosystem":"NuGet","cpePart":null,"purl":"pkg:nuget/OpenTelemetry.Exporter.OpenTelemetryProtocol","purlType":"nuget","versions":[{"text":"≥ 1.13.1, < 1.15.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.13.1, < 1.15.3","eol":null,"hubHref":null},{"vendor":"open-telemetry","product":"opentelemetry-dotnet","name":"opentelemetry-dotnet","label":"opentelemetry-dotnet","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.13.1, < 1.15.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.13.1, < 1.15.3","eol":null,"hubHref":"/vendor/open-telemetry/opentelemetry-dotnet"},{"vendor":"open-telemetry","product":"opentelemetry.exporter.opentelemetryprotocol","name":"OpenTelemetry.Exporter.OpenTelemetryProtocol","label":"opentelemetry.exporter.opentelemetryprotocol","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.13.1, < 1.15.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.13.1, < 1.15.3","eol":null,"hubHref":"/vendor/open-telemetry/opentelemetryexporteropentelemetryprotocol"},{"vendor":"opentelemetry","product":"opentelemetry","name":"opentelemetry","label":"opentelemetry","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.13.1, < 1.15.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.13.1, < 1.15.3","eol":null,"hubHref":"/vendor/opentelemetry/opentelemetry"}],"affectedCount":7,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-mr8r-92fq-pj8p","label":"github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-mr8r-92fq-pj8p","hostname":"github.com","tags":["X Refsource CONFIRM","Advisory","WEB","Mitigation","Vendor Advisory"]},{"url":"https://github.com/open-telemetry/opentelemetry-dotnet/pull/5980","label":"github.com/open-telemetry/opentelemetry-dotnet/pull/5980","hostname":"github.com","tags":["X Refsource MISC","FIX","WEB","Issue Tracking","Patch"]},{"url":"https://github.com/open-telemetry/opentelemetry-dotnet/pull/7064","label":"github.com/open-telemetry/opentelemetry-dotnet/pull/7064","hostname":"github.com","tags":["X Refsource MISC","FIX","WEB","Issue Tracking","Patch"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40891.json","label":"github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40891.json","hostname":"github.com","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40891","label":"nvd.nist.gov/vuln/detail/CVE-2026-40891","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/open-telemetry/opentelemetry-dotnet","label":"github.com/open-telemetry/opentelemetry-dotnet","hostname":"github.com","tags":["PACKAGE"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":["CGA-PX7W-F925-VH5P"]},"timeline":[{"kind":"published","date":"2026-04-23T17:54:36.033Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-04-23T18:23:08.858Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":21,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T03:26:17.929Z","stale":false,"partial":false}}