{"affected":[{"defaultStatus":"unaffected","ecosystem":"hex","packageName":"grpc_server","product":"grpc_server","source":"CNA: EEF","vendor":"elixir-grpc","versions":[{"lessThan":"1.1.0","status":"affected","version":"1.0.0","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"github","packageName":"elixir-grpc/grpc","product":"grpc_server","source":"CNA: EEF","vendor":"elixir-grpc","versions":[{"lessThan":"38955f1392cbf08eef231a347348445410455c85","status":"affected","version":"0332faae5f5e132314794dbfdae5edecbccea292","versionType":"git"}]},{"defaultStatus":"unaffected","ecosystem":"hex","packageName":"grpc","product":"grpc","source":"CNA: EEF","vendor":"elixir-grpc","versions":[{"lessThan":"1.0.0","status":"affected","version":"0.3.1","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"github","packageName":"elixir-grpc/grpc","product":"grpc","source":"CNA: EEF","vendor":"elixir-grpc","versions":[{"lessThan":"0332faae5f5e132314794dbfdae5edecbccea292","status":"affected","version":"6d8a09ad919e208fb600538ac8b19bd733a04310","versionType":"git"}]}],"cveId":"CVE-2026-121809","cwes":["CWE-400","CWE-835"],"description":"Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in elixir-grpc grpc_server and grpc allows unauthenticated attackers to occupy a BEAM scheduler indefinitely via a client-streaming or bidirectional-streaming request whose body ends inside a gRPC message.\n\nGRPC.Server.Adapters.Cowboy.read_stream/1 (grpc_server/lib/grpc/server/adapters/cowboy.ex, and the Cowboy adapter in grpc before the package split) asks for more data whenever the buffer does not hold a complete message. Once the request body has ended, every further read returns an empty chunk, so the buffer never changes and the function retries without end. A single 5-byte length prefix sent with END_STREAM keeps one scheduler busy for as long as the connection stays open, and repeated requests exhaust all schedulers.\n\nThis issue affects grpc_server: from 1.0.0 before 1.1.0; grpc: from 0.3.1 before 1.0.0.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":8.2,"severity":"high","source":"CNA: EEF","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":8.2,"severity":"high","source":"NVD: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","version":"4.0"}],"modifiedAt":1794598360114,"publishedAt":1794586717954,"references":[{"source":"CNA: EEF","tags":["vendor-advisory","related"],"url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-c2h9-f9cc-27xh"},{"source":"CNA: EEF","tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-121809.html"},{"source":"CNA: EEF","tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-121809"},{"source":"CNA: EEF","tags":["related"],"url":"https://github.com/elixir-grpc/grpc/commit/0332faae5f5e132314794dbfdae5edecbccea292"},{"source":"CNA: EEF","tags":["patch"],"url":"https://github.com/elixir-grpc/grpc/commit/38955f1392cbf08eef231a347348445410455c85"},{"source":"CNA: EEF","tags":["related"],"url":"https://github.com/elixir-grpc/grpc/commit/6d8a09ad919e208fb600538ac8b19bd733a04310"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://cna.erlef.org/cves/CVE-2026-121809.html"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://github.com/elixir-grpc/grpc/commit/0332faae5f5e132314794dbfdae5edecbccea292"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://github.com/elixir-grpc/grpc/commit/38955f1392cbf08eef231a347348445410455c85"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://github.com/elixir-grpc/grpc/commit/6d8a09ad919e208fb600538ac8b19bd733a04310"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-c2h9-f9cc-27xh"},{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","tags":[],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-121809"}],"remediation":[{"kind":"fix","source":"CNA: EEF","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/elixir-grpc/grpc/commit/38955f1392cbf08eef231a347348445410455c85"}],"revision":"47e99b1cb8e598e25c8c0bd2614f6b23d9355c3052847c3976e7d74f9361f5bb","sources":[{"modifiedAt":1794598360114,"name":"CNA: EEF","retrievedAt":1794600539591,"url":"https://www.cve.org/CVERecord?id=CVE-2026-121809"},{"modifiedAt":1794590239310,"name":"NVD","retrievedAt":1794594113427,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121809"}],"ssvc":{"assessedAt":1794592512226,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"CPU exhaustion via a truncated gRPC message on streaming RPCs in elixir-grpc grpc_server","updatedAt":1794600539591}