{"items":[{"id":"NVI-00018631","kind":"vulnerability","title":"OpenTelemetry eBPF Instrumentation: CPU-mismatch fallback uses 256-byte buffer with 8KB size","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-r6c9-g6q5-qrf9","CVE-2026-45681"],"plain_summary":"GitHub lists this reviewed advisory for go.opentelemetry.io/obi. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4713f41abe92ea268114b2f932a571da"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-06-09T10:58:38.000Z","value":"5.9 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4713f41abe92ea268114b2f932a571da"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-4713f41abe92ea268114b2f932a571da","url":"https://github.com/advisories/GHSA-r6c9-g6q5-qrf9","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-r6c9-g6q5-qrf9","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T20:56:39.448Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4713f41abe92ea268114b2f932a571da"],"technology":"go.opentelemetry.io/obi","known_exclusions":[],"conditions_summary":"### Summary\n\nThe per-CPU message-buffer fallback path uses a 256-byte backup buffer but preserves the original payload size, which can be up to 8KB. If a CPU mismatch occurs, OBI can read beyond the fallback buffer and leak adjacent memory into telemetry.\n\n### Details\n\nhttps://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/blob/032473449b53d9f02ec4619d4f5b84e6a81db362/bpf/common/http_buf_size.h#L4-L7\n\n`k_kprobes_http2_buf_size` is defined as 256 bytes, the size of the fallback buffer.\n\nhttps://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/blob/032473449b53d9f02ec4619d4f5b84e6a81db362/bpf/common/msg_buffer.h#L12-L36\n\nIntroduces 8KB per-CPU buffer and 256-byte `fallback_buf` in `msg_buffer_t`, creating a size mismatch for fallback use.\n\nhttps://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/blob/032473449b53d9f02ec4619d4f5b84e6a81db362/bpf/generictracer/k_tracer.c#L370-L394\n\nOn CPU mismatch, `fallback_buf `is used but size is still set to `m_buf->real_size` (up to 8KB) and passed downstream.\n\nhttps://github.com/open-telemetry/opentelemetry-ebpf-instrumentation/blob/032473449b53d9f02ec4619d4f5b84e6a81db362/bpf/generictracer/protocol_http.h#L4","public_affected_ranges":["< 0.9.0"]}],"null_published_at":"2026-11-07T07:07:39.864Z","source_updated_at":"2026-06-09T10:58:38.000Z","source_disclosed_at":"2026-05-18T20:11:20.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-06T20:56:39.448Z"}],"next_cursor":null,"snapshot_revision":"42594"}