The introduction of advanced reasoning capabilities have improved the
problem-solving performance of large language models, particularly on math and
coding benchmarks. However, it remains unclear whether these reasoning models
are more or less vulnerable to adversarial prompt attacks than their
non-reasoning counterparts. In this work, we present a systematic evaluation of
weaknesses in advanced reasoning models compared to similar non-reasoning
models across a diverse set of prompt-based attack categories. Using
experimental data, we find that on average the reasoning-augmented models are
\emph{slightly more robust} than non-reasoning models (42.51\% vs 45.53\%
attack success rate, lower is better). However, this overall trend masks
significant category-specific differences: for certain attack types the
reasoning models are substantially \emph{more vulnerable} (e.g., up to 32
percentage points worse on a tree-of-attacks prompt), while for others they are
markedly \emph{more robust} (e.g., 29.8 points better on cross-site scripting
injection). Our findings highlight the nuanced security implications of
advanced reasoning in language models and emphasize the importance of
stress-testing safety across diverse adversarial techniques.