More Agents Improve Math Problem Solving but Adversarial Robustness Gap Persists

Khashayar Alavi, Zhastay Yeltay, Lucie Flek, Akbar Karimi


Abstract
When LLM agents work together, they seem to be more powerful than a single LLM in mathematical question answering. However, are they also more robust to adversarial inputs? We investigate this question using adversarially perturbed math questions. These perturbations include punctuation noise with three intensities (10%, 30%, 50%), plus real-world and human-like typos (WikiTypo, R2ATA). Using a unified sampling-and-voting framework (Agent Forest), we evaluate six open-source models (Qwen3-4B/14B, Llama3.1-8B, Mistral-7B, Gemma3-4B/12B) across four benchmarks (GSM8K, MATH, MMLU–Math, MultiArith), with various numbers of agents n = 1,2,5,10,15,20,25. Our findings show that 1) Noise type matters: punctuation noise harm scales with its severity, and the human typos remain the dominant bottleneck, yielding the largest gaps to Clean accuracy and the highest attack success rate (ASR) even with a large number of agents; 2) Collaboration reliably improves accuracy as the number of agents, n, increases, with the largest gains from n=1 to n=5 and diminishing returns beyond n10. However, the adversarial robustness gap persists regardless of the agent count.
Anthology ID:
2026.findings-acl.2158
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
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Findings
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Publisher:
Association for Computational Linguistics
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Pages:
43457–43475
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2158/
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Cite (ACL):
Khashayar Alavi, Zhastay Yeltay, Lucie Flek, and Akbar Karimi. 2026. More Agents Improve Math Problem Solving but Adversarial Robustness Gap Persists. In Findings of the Association for Computational Linguistics: ACL 2026, pages 43457–43475, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
More Agents Improve Math Problem Solving but Adversarial Robustness Gap Persists (Alavi et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2158.pdf
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