At least two distinct vendor advisory assurances published after issuance and on or before 2027-01-31T23:59Z, each stating a vulnerability is not known to be exploited, are retrospectively undermined by 2027-04-26T12:30Z by documented exploitation evidence dated before the assurance (same-day pairs only with reliable ordering).
OPEN
- id
- SO-2026-016
- class
- EVENT
- claim
- At least two distinct vendor advisory assurances published after issuance and on or before 2027-01-31T23:59Z, each stating a vulnerability is not known to be exploited, are retrospectively undermined by 2027-04-26T12:30Z by documented exploitation evidence dated before the assurance (same-day pairs only with reliable ordering).
- issued
- 2026-10-26T12:30:00Z
- probability
- 0.5
- benchmark
- 0.45
- benchmark kind
- ANALYST_PRIOR
- benchmark basis
- One reversal on the conduct ledger since the 27 Aug reset (Ahsay); one held candidate (Microsoft SharePoint). About one per eight weeks at CHQ's collection; Poisson 1.8 expected in a 14-week assurance window gives 0.54 for two or more, shaded down for narrow collection. A prior, stated as such.
- adjustment
- 0.05
- resolution rule
- Counting unit: one vendor, one advisory, one assurance, one undermining evidence item. YES if two or more units satisfy: assurance archived in original wording, published in the assurance window; undermining evidence (vendor revision, catalog listing with exploitation date, responder report) at or before RESOLUTION_TS; exploitation date before the assurance date, or same day with reliable timestamps or independently established ordering; identifiers match. Interpretation: measures reliability as a risk input; no claim of falsity or knowledge.
- admissibility
- Assurances before ISSUED_TS cannot qualify; Grade A or B with stated date on the undermining evidence; exclusions: statements overtaken by later exploitation, severity-only revisions, unarchivable assurances.
- exclusions
- statements overtaken by later exploitation, severity-only revisions, unarchivable assurances.
- resolves
- 2027-04-26T12:30:00Z
- status
- OPEN
- outcome date
- Not recorded
- outcome basis
- Not recorded
- brier
- Not recorded
- benchmark brier
- Not recorded
- resolution source
- EXTERNAL
- experimental
- false
- false positive cost
- Counting routine exploitability-index revisions would resolve YES in any quarter.
- ledger hash
- 17fc34056e1e81f5
- revision log
- 2026-11-06 (CHQ-CORR-2026-033): ledger hash corrected from the shared placeholder c2f1ab40c70d9013 to the per-entry digest 17fc34056e1e81f5, recomputed from the declared serialization of identifier, claim, probability, issued timestamp and resolution rule. Claim, probability, issued timestamp and resolution rule unchanged.
- record links