mlsanityData to 14 Oct 2026

Streaming Hallucination Detection in Long Chain-of-Thought Reasoning

arXiv 2601.02170 ↗First posted 5 Jan 2026cs.AIcited by 5

On the map: LLM reasoning → Hallucination detection and mitigation

Abstract (arXiv)

Long chain-of-thought (CoT) reasoning improves the performance of large language models, yet hallucinations in such settings often emerge subtly and propagate across reasoning steps. We suggest that hallucination in long CoT reasoning is better understood as an evolving latent state rather than a one-off erroneous event. Accordingly, we treat step-level hallucination judgments as local observations and introduce a cumulative prefix-level hallucination signal that tracks the global evolution of the reasoning state over the entire trajectory. Overall, our approach enables streaming hallucination detection in long CoT reasoning, providing real-time, interpretable evidence.

Key facts. Cited by 5 papers in the map (data through 14 Oct 2026). Placed in Hallucination detection and mitigation, one of 17 directions in LLM reasoning. Builds on 14 of its 50 references that are in the map. First posted on arXiv 5 Jan 2026.

Builds on

14 of 50 references.

Closest ancestors · 3

Same direction, newest first

  1. 2025Are Reasoning Models More Prone to Hallucination?29 May
  2. 2025Auditing Meta-Cognitive Hallucinations in Reasoning Large Language Models19 May
  3. 2025Detection and Mitigation of Hallucination in Large Reasoning Models: A Mechanistic Perspective19 May

Other references · 11

  1. 2022Challenging BIG-Bench Tasks and Whether Chain-of-Thought Can Solve Themcited by 1,807
  2. 2023The Geometry of Truth: Emergent Linear Structure in Large Language Model Representations of True/False Datasetscited by 712
  3. 2024Is DPO Superior to PPO for LLM Alignment? A Comprehensive Studycited by 262
  4. 2025Reasoning Models Know When They're Right: Probing Hidden States for Self-Verificationcited by 159
  5. 2024Thermometer: Towards Universal Calibration for Large Language Modelscited by 38
  6. 2025Rethinking External Slow-Thinking: From Snowball Errors to Probability of Correct Reasoningcited by 36
  7. 2025Probing the Geometry of Truth: Consistency and Generalization of Truth Directions in LLMs Across Logical Transformations and Question Answering Taskscited by 18
  8. 2025Explainable Chain-of-Thought Reasoning: An Empirical Analysis on State-Aware Reasoning Dynamicscited by 16
  9. 2025Temporalizing Confidence: Evaluation of Chain-of-Thought Reasoning with Signal Temporal Logiccited by 11
  10. 2025Cross-Layer Attention Probing for Fine-Grained Hallucination Detectioncited by 4
  11. 2025PlanU: Large Language Model Reasoning through Planning under Uncertaintycited by 4

Built on by

Cited by year (2026 to 14 Oct)

Citing papers per year: 2026: 5.

5 papers.

  1. 2026Monitoring the Internal Monologue: Probe Trajectories Reveal Reasoning Dynamicscited by 5
  2. 2026The Reasoning Trap: An Information-Theoretic Bound on Closed-System Multi-Step LLM Reasoningcited by 2
  3. 2026Reasoning Denoiser: Denoising Reasoning Traces for Hallucination Detection in Large Reasoning Modelscited by 1
  4. 2026Tool Specifications Matter: Uncovering and Mitigating Safety Risks in AI Agentscited by 1
  5. 2026Harnessing Reasoning Trajectories for Hallucination Detection via Answer-agreement Representation Shapingcited by 0

Similar, not cited

Close in wording, no citation either way

  1. 2025Hallucination Detection via Internal States and Structured Reasoning Consistency in Large Language Models
  2. 2025Chain-of-Thought Prompting Obscures Hallucination Cues in Large Language Models: An Empirical Evaluation
  3. 2026Sanity Checks for Long-Form Hallucination Detection
  4. 2025Joint Evaluation of Answer and Reasoning Consistency for Hallucination Detection in Large Reasoning Models
  5. 2026Scalable Token-Level Hallucination Detection in Large Language Models
  6. 2026HalluGuard: Demystifying Data-Driven and Reasoning-Driven Hallucinations in LLMs
  7. 2026Generating Effective CoT Traces for Mitigating Causal Hallucination
  8. 2026Attention Dispersion as a Diagnostic Signal for Hallucination in Large Language Models