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Hermes Threat Trajectory (HTR) Methodology

  • Hermes Threat Score (HTS): Measures the current instantaneous operational risk on a scale from 0 to 100.
  • Hermes Threat Trajectory (HTR): Measures the direction, velocity, and second-derivative acceleration of that risk across a rolling temporal horizon ($T-30$ to $NOW$).
Static Snapshot (HTS = 78) --> Tells you where the risk is right now.
Dynamic Vector (HTR = ACCELERATING, v = +4.2 pts/day) --> Tells you where the risk will be tomorrow.

Below is an operational visualization of a critical asset exhibiting rapid exploit acceleration:

THREAT TRAJECTORY (HTR)

CVE-2026-76460 — Cisco Identity Services Engine (ISE) — Token-Replay Authentication Bypass

ACCELERATING
⚡ +4.8 pts/day
100 50 0 T-21 42 T-14 55 T-5 82 NOW 99
HTS (NOW) 99 Operational Risk
HTR TRAJECTORY ACCELERATING v = +4.8 | a = +1.6
CVSS v3.1 10 Intrinsic Severity
EPSS PROB. 92% Statistical Model
CISA KEV ACTIVE Known Exploited
⚖️ METRIC DIVERGENCE ANALYSIS:

While CVSS 10.0 signaled maximum theoretical severity from day one, HTR tracked the true operational escalation: a dormant flaw jumping from an internal tracker (HTS 42) to weaponized exploitation and KEV integration within 14 days, with explosive velocity (+4.8 pts/day).


Velocity measures the average daily change in Hermes Threat Score across an observation window $\Delta t$:

v = (HTS_t2 - HTS_t1) / (t2 - t1) [units: points / day]

Acceleration measures the rate at which risk momentum is intensifying or tapering off:

a = (v_current - v_previous) / Delta_t [units: points / day^2]

A positive acceleration ($a > 0$) combined with high velocity signifies an exploit weaponization sprint (threat actors rapidly incorporating the vulnerability into botnets or ransomware kits).


Rather than arbitrary qualitative labels, HTR applies deterministic state classifications:

ClassificationTechnical CriteriaStrategic Defender Decision
ACCELERATING$v \ge +2.0$ pts/day or weaponized PoC / in-the-wild exploitation within 72 hours.Emergency Out-of-Band Patch
EMERGINGNewly disclosed zero-day or high-exposure surface with active research reconnaissance.Pre-Emptive Perimeter Shielding
STABLE$-0.5 \le v \le +0.5$ pts/day; established mitigation available; no novel exploit chains.Standard Patching Maintenance
DECELERATING$v \le -1.0$ pts/day; widespread vendor patching or deprecated software ecosystem.Deprioritize to Standard Cycle
VOLATILEContradictory telemetry, disputed vendor advisories, or fluctuating honeypot hits.Enhanced Sensor Monitoring
INSUFFICIENT_DATASparse telemetry; pending official disclosure or missing protocol captures.Track Primary Feeds

Hermes does not claim that HTS or HTR make other metrics obsolete; rather, they serve distinct operational purposes:

Metric Nature Primary Question Answered
----------------------------------------------------------------------------------------
CVSS Theoretical Inherent "How destructive could this be under ideal conditions?"
EPSS Statistical Likelihood "What is the statistical chance of exploitation in 30d?"
CISA KEV Observed Historical "Has this been seen exploited in the wild anywhere?"
HTS Operational Relevance "How urgently do we need to patch this right now?"
HTR Temporal Trajectory "Is the adversary momentum speeding up or dying down?"