This volume contains the abstracts of the posters accepted and presented at the EuroS&P 2023 conference, which was held on July 3-6, 2023 in Delft, the Netherlands. Following the tradition initiated with the 2022 edition of the conference, these proceedings are published on Zenodo (https://zenodo.org), an open research repository operated by CERN, which enables sharing and preserving of research outputs. The poster session of Euro S&P is conceived as an opportunity for security and privacy researchers to share their recent results, and to obtain valuable feedback on their ongoing work from participants at the conference. In total, 8 abstracts were submitted to the poster session, which underwent a lightweight review process. In particular, reviews were aimed at checking the coherence of the abstracts with the scope of Euro S&P, rather than providing in-depth technical feedback as for a regular submission. Each abstract was reviewed by at least two members of the program committee. After the review phase, the program committee decided to accept all submitted abstracts. I would like to thank all the authors for their submissions, and especially the poster presenters to have brought up to life an interesting poster session at the conference. I am also indebted to the program committee of the Euro S&P poster session, for their timely and useful reviews. I would also like to thank the general chairs of Euro S&P 2023, Kaitai Liang and Georgios Smaragdakis; the program chairs David Evans and Herbert Bos; the publication chairs Luca Verderame and Stefanie Roos. Finally, I am also grateful to Ivan Liang for setting up the HotCRP platform for managing the submission process, and to the web chair Roland Kromes for updating the website with the updates related to the call for posters. Luca Mariot, University of Twente, the Netherlands IEEE European Symposium on Security and Privacy 2022 Poster Chair