Relevance as a Vulnerability: How Web Retrieval Degrades Safety Alignment in LLM Agents

Aditya Nawal, Manit Baser, Mohan Gurusamy


Abstract
AI agents augment large language models with external tools such as web retrieval, enabling grounded and up-to-date responses. However, incorporating external content into the generation pipeline can weaken the safety alignment mechanisms that govern model outputs. Prior work shows that enabling retrieval in agents increases compliance with harmful requests. We introduce AgentREVEAL, a diagnostic framework for analyzing retrieval-induced safety degradation in LLM agents. The framework examines two axes: how retrieval is integrated into the agent pipeline and the properties of the retrieved content. Along the integration axis, we find that binding tool invocation and response generation in a single step amplifies harmful outputs. Along the content axis, we uncover the Safe Source Paradox: even oppositional or safety-oriented sources, such as pages containing warnings or risk disclaimers, can increase harmful compliance by an average of 25% compared to the no-retrieval baseline. Finally, we show that relevance acts as a shared activation condition for both vulnerabilities. We observe that several agents retrieve information for harmful requests in the autonomous retrieval setting, while harmful compliance remains elevated despite several retrieval-pipeline interventions and defenses. Because relevance is also what makes retrieval useful, these results expose a safety-utility trade-off for retrieval-enabled agents. We introduce HarmURLBench, a benchmark containing 1,405 real-world URLs paired with 320 harmful behaviors to support future evaluations.
Anthology ID:
2026.findings-emnlp.2408
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
51720–51746
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2408/
DOI:
10.18653/2026.findings-emnlp.2408
Bibkey:
Cite (ACL):
Aditya Nawal, Manit Baser, and Mohan Gurusamy. 2026. Relevance as a Vulnerability: How Web Retrieval Degrades Safety Alignment in LLM Agents. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 51720–51746, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Relevance as a Vulnerability: How Web Retrieval Degrades Safety Alignment in LLM Agents (Nawal et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.2408.pdf