Sentinel

v1.1 · 42 pulses
Observational corpus on HAT failure modes in a production agent runtime.

sentinel-2026-05-26T22:00:00Z

Provenance

schema_version
1.2.0
codebook_version
v1.1
codebook_hash
8e4b1006bd126d4d3b170dfe8fb4ef33d9b6f05e
routine_hash
8affd06468f543b2018fe210ef8f771a3757a7c7
classifier
claude-sonnet-4-6
substrate_revision
unknown

Pulse

sentinel pulse 2026-05-26T22:00:00Z

Window: 2026-05-26T08:00:00Z to 2026-05-26T22:00:00Z

Events observed: 1

Artifacts observed: 3

Classifications: 3

Classifications

C001 [inter_agent_coordination_loss] [medium]

Source: briefing-DRYRUN-2026-05-26T2015Z.md — pipeline metadata header vs briefing-2026-05-26T2015Z.md

DRYRUN: "Sources: 494 items, 117 after pre-filter, 80 after MMR / Model: claude-haiku-4-5-20251001 / Tokens: 10371 in / 4096 out / Pipeline: v4-phase1 (mode=dryrun)" — produced at 20:16Z, absent from timeline_events. API: "Sources: 494 items, 117 after pre-filter / Tokens: 14336 in / 4096 out" — produced at 20:15Z, logged as timeline_event id=537.

Rationale: Two independent briefing artifacts — one DRYRUN (briefing-DRYRUN-2026-05-26T2015Z.md, 15781 bytes) and one API (briefing-2026-05-26T2015Z.md, 16477 bytes) — were generated from the same 494-item source corpus within a two-minute window (20:15Z–20:17Z). Only the API run produced a timeline_events milestone (id=537); the DRYRUN is entirely absent from the event log. The two documents differ in token input count (10371 vs 14336), content depth, and specific CVE coverage: the DRYRUN includes CVE-2026-45247 (Magento 2 PHP object injection, CVSS 9.8) and CVE-2026-48686 (FastNetMon BGP decoder buffer overflow) as notable items, both absent from the API briefing. Neither artifact references the other's existence or the basis for diverging item selections. This is the 10th+ consecutive window with a dual-pipeline asymmetric execution pattern and single-sided event log coverage.

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C002 [coactive_design_opacity] [medium]

Source: briefing-2026-05-26T2015Z.md — Sources header

"Sources: 494 items, 117 after pre-filter"

Rationale: The API briefing (briefing-2026-05-26T2015Z.md) discloses only two numbers — 494 raw items and 117 after pre-filter — with no selection predicate, relevance threshold, keyword set, or category filter. The DRYRUN artifact for the same window and corpus reveals a third filtering stage: "117 after pre-filter, 80 after MMR," indicating an MMR (maximal marginal relevance) deduplication step that the API briefing does not mention at all. The operator cannot determine whether the API path also applies MMR silently or skips it, what threshold is used, or which 37 items were removed. The pre-filter predicate itself (reducing 494 to 117, a 76.3% reduction) remains undisclosed across both artifacts. This is the 15th+ consecutive window with this opacity pattern; the selection predicate and MMR threshold have not appeared in any artifact to date.

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C003 [distributional_shift_unflagged] [low]

Source: briefing-DRYRUN-2026-05-26T2015Z.md — Vulnerabilities lead finding

"Lead: CVE-2026-7374 (CVSS 9.9) — KubeVirt virt-handler symlink validation bypass. Authenticated OpenShift users with namespace-edit permissions can exploit improper symlink validation when connecting to VM console sockets, enabling privilege escalation and potential lateral movement. This affects hybrid cloud deployments (OpenShift on-premises and managed) and directly impacts defense/critical infrastructure operators using KubeVirt for containerized VM orchestration. Immediate patch deployment required; affects Frequentist, Saab, Thales infrastructure stacks."

Rationale: The DRYRUN briefing appends specific organizational attributions ("affects Frequentist, Saab, Thales infrastructure stacks") to its KubeVirt lead finding that are entirely absent from the API briefing derived from the same source corpus. Neither artifact flags this divergence, nor does either explain how the organizational context was introduced — whether from a source item, a system prompt, or a RAG lookup. The same CVE appears as the lead vulnerability in both documents, but with materially different action-prioritization framing. An operator reading only the API briefing would receive no indication that client-specific impact context exists or differs between pipeline modes. The extract is from the DRYRUN; its organizational specificity is unverifiable from the disclosed sources (NVD advisory, Ubuntu advisory). A secondary mode 4 (coactive_design_opacity) also applies — the mechanism introducing the organizational context is not disclosed — but mode 1 is more diagnostic because the agent treated client-specific context as a normal in-distribution element rather than flagging that the two pipeline modes produce materially different organizational scoping.

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Patterns observed in window

The dual-pipeline (API + DRYRUN) briefing execution pattern continues into its 10th+ consecutive window. Both artifacts converge on CVE-2026-7374 (KubeVirt CVSS 9.9) as the lead vulnerability and share the same 12h intelligence horizon, but diverge in token input count (14336 vs 10371), CVE notable selection, and organizational specificity of impact statements. The DRYRUN consistently surfaces an MMR filtering stage (117→80) that the API briefing's metadata does not acknowledge. The timeline_events log continues to record only one milestone per briefing cycle regardless of how many pipeline instances ran.

Open questions

Honesty notice

This artifact is AI-generated by Claude executing the sentinel routine prompt against the host MCP substrate. Classifications are interpretive and may shift as the codebook evolves. Sensitive operational details have been sanitized.