Security Engineer Intern (Summer 2026) at Poshmark

ABOUT POSHMARK Poshmark is the leading fashion marketplace where style comes alive through discovery, self-expression, and human connection. Powered by a vibrant community of 165 million members, Poshmark brings real people and taste to shopping through a social experience shaped by shared discovery. Buying and selling fashion feels simple, joyful, and personal, while every item tells its own story. Poshmark empowers sellers to grow meaningful businesses, keeps fashion in circulation longer, and gives shoppers access to unique and trusted finds, from everyday pieces to one-of-a-kind vintage and luxury. 🎯 ABOUT THE ROLE The Product Security Intern will join Poshmark's Security organization, working alongside experienced security engineers and GRC team to help protect the products and platform. This role focuses on identifying vulnerabilities, supporting secure development practices, and strengthening security across Poshmark's software ecosystem. The intern will gain meaningful, real-world exposure to product security in a fast-moving consumer tech environment — contributing work that directly impacts platform integrity and member trust. ⚙️ WHAT YOU’LL DO - Conduct vulnerability assessments and assist with penetration testing across Poshmark's web and mobile product surfaces. - Perform secure code reviews to identify common security weaknesses (e.g., OWASP Top 10) within the software development lifecycle and help improve documentation. - Assist in triaging and documenting findings from SAST/DAST tooling, working with engineering teams to prioritize remediation. - Collaborate with software engineers to promote security best practices. - Support the creation or improvement of internal security documentation, guidelines, and developer-facing checklists. - Help track and manage vulnerability findings and remediation workflows in JIRA. 💡WHAT YOU’LL BRING - Currently pursuing a bachelor’s degree in computer science, computer engineering, Information Security, cybersecurity, or a related field. - Foundational understanding of web application security concepts and common vulnerability classes. - Familiarity with secure coding practices and the software development lifecycle. - Ability to communicate technical findings clearly in written and verbal form. Standard Requirements for All Interns - Demonstrated interest in Poshmark’s mission, community, or industry - Current or rising senior enrolled in an accredited university, or recent college graduate - Seniors should expect to graduate between Fall 2026 and Summer 2027 - Strong communication, collaboration, and curiosity - Available to work a M-F 5-day work schedule between 8am-5pm - Willing to commute 5x per week to PMHQ in Redwood City, CA - No employment sponsorship required now or in the future