{"schema_version":"0.10.0","id":"LR-2026-0292","record_version":2,"title":"Anthropic Claude model develops working Linux kernel MPTCP root exploit (CVE-2026-98432)","verification":{"human_verified":false,"method":"automated_gate","auto_verified":true,"score":50.8,"score_breakdown":{"source_authority":12.1,"independent_corroboration":7.0,"implicated_party_confirmed":0.0,"citation_integrity":14.0,"specificity":6.0,"completeness":4.16,"unhedged_language":5.0},"checks":{"schema_valid":true,"every_field_cited":true,"quotes_verbatim":true,"source_fetched":true,"distinct_incident":true,"dates_plausible":true,"sources_agree":true,"source_describes_incident":true,"severe_backed_by_source":true,"record_integrity":true,"eligible":true,"about_this_case":true},"gate_version":"gate-2026-10-18.7","cross_check_model":null,"cross_check_agreement":null,"duplicate_of":null,"verified_by":null,"verified_at":"2026-10-31","extraction_run_id":null,"evidence_level":{"level":"preliminary","reason":"1 report: BleepingComputer · subject to change","original_document":null,"reports_total":1,"reports_independent":1,"reports_derivative":0,"developing":true,"disputed":false,"rules_version":"evidence-2026-10-29.1","computed_at":"2026-10-31","history":[{"date":"2026-10-31","from_level":null,"to_level":"preliminary","reason":"1 report: BleepingComputer · subject to change"}]},"sources_hash":"6617c8ee53373e8872f5f73d715a2d396aca4428a8baa567862aead04ad640f3"},"system":{"model_name":"Claude","model_version":null,"developer":"Anthropic","harness":null,"tools_granted":[],"permissions_scope":null,"autonomy_level":"unknown","guardrails_present":[],"deployment_context":"research","tier":"provider","lifecycle_stage":"pre_release","integration_type":null,"intended_use":"Security research: developing an exploit for a Linux kernel vulnerability","safeguard_state":null,"production_intended":null},"event":{"date_occurred":null,"date_disclosed":"2026-10-30","incident_class":"security_compromise","failure_class":null,"agent_involved":true,"secondary_failure_classes":[],"trigger":"unknown","duration":null,"detection_method":"unknown","summary":"Anthropic researchers reported that an unreleased Claude AI model developed an exploit for CVE-2026-98432, a use-after-free race condition in the Linux kernel's IPv4 TCP code affecting kernels back to 4.4.","tags":[],"date_detected":null,"near_miss":null,"root_cause":null,"root_cause_detail":null,"failure_class_detail":null,"responsible_party":null,"adversarial_actor":"none","input_provenance":null,"time_to_contain":null,"operations_paused":null,"remediation":"The vulnerability was fixed in the upstream Linux kernel and backported to maintained kernel branches.","precursor_events":null},"impact":{"direct_loss_usd":null,"remediation_hours":null,"records_exposed":null,"third_parties_affected_count":null,"severity":"minor","severity_because":"minor: The exploit was demonstrated in a research setting against a single Linux server running an MPTCP listener, with no confirmed in-the-wild exploitation.","harm_class":[],"affected_description":"a Linux server running an MPTCP listener","protected_class_involved":null,"data_categories_exposed":[],"loss_range_usd":null,"reversibility":null,"downstream_exposure_count":null},"evidence":{"sources":[{"url":"https://www.bleepingcomputer.com/news/security/critical-linux-kernel-flaw-allows-remote-root-attacks-on-mptcp-servers/","publisher":"BleepingComputer","date":"2026-10-30","type":"press","title":"Critical Linux kernel flaw allows remote root attacks on MPTCP servers","archived_url":null,"attachment":"first_report","independence":"independent"}],"per_field_confidence":{"system.model_name":"C","system.tier":"D","system.lifecycle_stage":"C","system.intended_use":"D","system.developer":"C","system.deployment_context":"D","system.autonomy_level":"D","event.adversarial_actor":"D","event.remediation":"D","event.agent_involved":"C","event.incident_class":"D","event.summary":"D","event.date_disclosed":"A","event.trigger":"D","event.detection_method":"D","impact.affected_description":"C","impact.severity":"D","context.industry":"D","context.systemic_exposure":"D","context.denominator_available":"D","context.country":"D","impact.severity_because":"D"},"field_citations":{"system.model_name":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"system.developer":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"system.lifecycle_stage":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"system.deployment_context":[{"source_index":0,"quote":"Security researchers at Anthropic have developed an exploit for a critical Linux kernel vulnerability that allows unauthenticated attackers to remotely execute commands as root on servers running Multipath TCP (MPTCP) listeners."}],"system.intended_use":[{"source_index":0,"quote":"Security researchers at Anthropic have developed an exploit for a critical Linux kernel vulnerability that allows unauthenticated attackers to remotely execute commands as root on servers running Multipath TCP (MPTCP) listeners."}],"event.agent_involved":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"event.adversarial_actor":[{"source_index":0,"quote":"There are currently no confirmed reports of CVE-2026-98432 being exploited in the wild."}],"event.incident_class":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"impact.affected_description":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"impact.severity_because":[{"source_index":0,"quote":"There are currently no confirmed reports of CVE-2026-98432 being exploited in the wild."}],"context.industry":[{"source_index":0,"quote":"Security researchers at Anthropic have developed an exploit for a critical Linux kernel vulnerability that allows unauthenticated attackers to remotely execute commands as root on servers running Multipath TCP (MPTCP) listeners."}],"context.country":[{"source_index":0,"quote":"Security researchers at Anthropic have developed an exploit for a critical Linux kernel vulnerability that allows unauthenticated attackers to remotely execute commands as root on servers running Multipath TCP (MPTCP) listeners."}],"context.systemic_exposure":[{"source_index":0,"quote":"The vulnerability affects Linux kernels dating back to version 4.4, including widely used distributions such as Ubuntu, Red Hat Enterprise Linux (RHEL), and Rocky Linux."}],"event.summary":[{"source_index":0,"quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener."}],"event.remediation":[{"source_index":0,"quote":"The vulnerability was fixed in the upstream Linux kernel and backported to maintained kernel branches."}],"impact.severity":[{"source_index":0,"quote":"There are currently no confirmed reports of CVE-2026-98432 being exploited in the wild."}],"event.date_disclosed":[{"source_index":0,"quote":"published: 2026-10-30"}]},"notes_on_gaps":"Only one source (BleepingComputer) is present. No source states who first noticed the exploit, so detection_method is left unwritten and story.caught is null. No source states the trigger, root cause, failure_class, autonomy level, tools granted, guardrails, permissions scope, harness, model version, date occurred, date disclosed, loss figure, records exposed, third-party count, or remediation hours; these are omitted. event.incident_class=security_compromise is a grade-D classification: the cited sentence describes the model's exploit breaching a target server's kernel boundary (root execution), not the model's own sandbox; no source states an attacker or injected instruction. event.adversarial_actor=none rests on the absence of confirmed in-the-wild exploitation. context.industry and context.country are inferred from Anthropic being a US company; no source states them. impact.severity=minor rests on the research setting and no confirmed third-party harm. The 53-minute figure is the exploit's runtime, not a detection-to-containment span, so no bounds are given. system.tier: provider by rule (deployment_context research). [aggregated by deepseek-chat, aggregate-2026-09-27.1, 2026-10-31] system.intended_use: research. system.deployment_context: research. system.autonomy_level: no source states the arrangement. event.adversarial_actor: none. event.remediation: classified from described behaviour. event.incident_class: the system's own boundary (sandbox, permissions, weights, accounts) was breached. event.summary: classified from described behaviour. event.trigger: no source states a cause. event.detection_method: no source says who first noticed. context.industry: Information. context.systemic_exposure: classified from described behaviour. context.denominator_available: no denominator is available for this incident. context.country: US."},"context":{"industry":"Information","org_size_band":null,"country":"US","denominator_available":false,"denominator":null,"related_incident_ids":[],"systemic_exposure":false,"shared_model_id":null,"upstream_incident_id":null,"incident_evidence":null,"regulatory":null,"coverage":null},"narrative":{"steps":[{"step":"doing","text":"Anthropic security researchers had an unreleased Claude model develop an exploit for CVE-2026-98432, a Linux kernel TCP use-after-free race condition, targeting a server running an MPTCP listener.","quote":"An Anthropic report explained that an unreleased Claude AI model developed an exploit that bypassed kernel address space layout randomization (KASLR) and executed arbitrary commands as root on a Linux server running an MPTCP listener.","source_index":0,"grade":"C"},{"step":"went_wrong","text":"The model produced a working remote exploit that bypassed KASLR and ran commands as root, showing the flaw went beyond the denial-of-service impact Red Hat assessed.","quote":"According to Anthropic, the exploit took about 53 minutes to achieve remote root code execution, showing the vulnerability could be exploited for more than denial-of-service attacks.","source_index":0,"grade":"C"},{"step":"reached","text":"It reached root-level command execution on a Linux server running an MPTCP listener; the flaw also affects ordinary TCP connections and kernels back to 4.4 across Ubuntu, RHEL and Rocky Linux.","quote":"The flaw, tracked as CVE-2026-98432, also affects ordinary TCP connections, although remote code execution has not been publicly demonstrated on servers without an MPTCP listener.","source_index":0,"grade":"C"},{"step":"done","text":"The vulnerability was fixed upstream and backported to maintained kernel branches; Debian, Oracle Linux, Amazon Linux and SUSE released fixes while Ubuntu and RHEL fixes were pending, and CIQ shared temporary firewall and nftables mitigations.","quote":"The vulnerability was fixed in the upstream Linux kernel and backported to maintained kernel branches.","source_index":0,"grade":"C"}],"model":"deepseek-chat","prompt_version":"aggregate-2026-09-27.1","extracted_at":"2026-10-31","source_urls":["https://www.bleepingcomputer.com/news/security/critical-linux-kernel-flaw-allows-remote-root-attacks-on-mptcp-servers/"]}}