Corrosion is commonly observed in reclaimed steel elements, often leading to significant challenges for their reuse. Corrosion potentially might favor failure in the cross-section, by yielding or local buckling due to the reduction of the plate thickness. The buckling resistance of the member or structure may also be affected for the same reason. This paper examines numerically the effect of corrosion on the cross-section bending resistance as it represents the reference both for members sensitive to buckling and restrained members. In particular, two cross-sections are considered hereafter: HEA200 and HEAA260. A finite element model is developed in ANSYS and compared to existing test results obtained for members subjected to uniaxial and biaxial bending moments but without corrosion. Then, a sensitivity study is performed on these two short members varying the shape of the corrosion area as well as the thickness of the corrosion. The comparison of the cross-sectional resistance obtained numerically with the design rules of Eurocode 3 Part 1-1 highlights that the major-axis bending moment is the most critical loading situation.