CVE-2026-9520: blitz-js blitz Sign-in LoginForm.tsx cross site scripting

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-26 · updated 2026-07-23
Weakness: CWE-79

Description

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.

Affected products

blitz-js blitz: 3.0.0, 3.0.1, 3.0.2

References

https://gist.github.com/TrebledJ/164c7ca6c8208b63e6937bc11984720b
https://vuldb.com/submit/814378
https://vuldb.com/vuln/365540
https://vuldb.com/vuln/365540/cti

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