{"schema":"threatline.record/2","record":{"id":"CVE-2026-86147","aliases":[],"summary":"Apache bRPC: Arbitrary file creation/truncation via /flags and unbounded profiling duration via /pprof","details":"External control of file name or path and uncontrolled resource consumption in Apache bRPC (version < 1.18.0) on all platforms allows remote attackers who can reach the builtin service port to create directories and truncate/overwrite files with the privileges of the server process, or to hold the process-wide CPU/contention profiler for an arbitrarily long time.\n\nRoot Cause:\n1. The builtin /flags service allows gflags carrying a validator to be modified at runtime via ?setvalue=. The bvar/mbvar dump path gflags (bvar_dump_file, bvar_dump_tabs, mbvar_dump_file) were registered with an accept-anything validator whose only purpose was to wake the dumping thread. A remote attacker could therefore repoint the dump path (e.g. GET /flags/bvar_dump_file?setvalue=/victim/dir/target followed by GET /flags/bvar_dump?setvalue=true, or the equivalent for mbvar_dump_file, which is used verbatim without a forced suffix), making the dumping thread recursively create directories and open/truncate files at attacker-chosen locations. Tab names in bvar_dump_tabs were appended to the path without sanitization, allowing '..' to escape the configured directory.\n2. The /pprof builtin service did not clamp the ?seconds= parameter to FLAGS_max_profiling_seconds (a limit that /hotspots enforced). A single request such as ?seconds=2147483647 made the handler sleep for decades while holding the process-wide gperftools CPU profiler or bthread contention profiler, so /hotspots/cpu and /hotspots/contention returned 503 for everyone else during that time.\n\nAffected Scenarios:\nAny Apache bRPC server exposing the builtin services (enabled by default on the same port as normal RPC traffic) to untrusted networks.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3523 \n\nNote:\nAfter the fix, bvar_dump_file, bvar_dump_tabs and mbvar_dump_file can no longer be modified at runtime through the /flags builtin service. They can still be changed programmatically via google::SetCommandLineOption(), taking effect on the next dump cycle. The profiling duration of /pprof is now capped by the -max_profiling_seconds gflag (default 300 seconds), which can be adjusted by the server owner.","categories":["Frameworks"],"product":"Apache bRPC","vendor":"Apache Software Foundation","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-86147","source_modified_at":"2026-10-21T12:16:22.369Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Apache bRPC","vendor":"Apache Software Foundation","versions":[{"status":"affected","version":"0","lessThan":"1.18.0","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-86147","source_modified_at":"2026-10-21T12:16:22.369Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Apache bRPC","ecosystem":null},"version":"1.18.0","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00203,"percentile":0.09754,"score_date":"2026-10-23"},"published_at":"2026-10-21T12:16:22.369Z","modified_at":"2026-10-21T12:16:22.369Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-86147","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:16:22.369Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-86147","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb","tags":["vendor-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:16:22.369Z","content_hash":"02e44beeb3b45577517d74c32c1cc6c69a8d0fd3d18392c928bcaa926710809d"}}