CVE-2026-9520: Blitz has a Cross-site Scripting issue

May 26, 2026 (updated June 30, 2026)

A weakness has been identified in blitz-js blitz up to 3.0.2 on GitHub. This impacts an unknown function of the file packages/generator/templates/app/src/app/auth/components/LoginForm.tsx of the component Sign-in. This manipulation of the argument Next causes cross site scripting. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

References

gist.github.com/TrebledJ/164c7ca6c8208b63e6937bc11984720b
github.com/advisories/GHSA-h2p9-cr4h-px24
nvd.nist.gov/vuln/detail/CVE-2026-9520
vuldb.com/submit/814378
vuldb.com/vuln/365540
vuldb.com/vuln/365540/cti

Code Behaviors & Features

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