PT-2026-38270 · Flight · Flight

Published 2026-05-06 · Updated 2026-05-13 · CVE-2026-42548

Positive Technologies (AI Summary)

CVSS v4.0

8.6

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Name of the Vulnerable Software and Affected Versions Flight versions prior to 3.18.1

Description The Flight::jsonp() function concatenates the jsonp query parameter directly into an application/javascript response body without validating if the value is a legal JavaScript identifier. This allows an attacker to inject arbitrary JavaScript that executes in the response origin, leading to reflected cross-site scripting (XSS), which can result in cookie theft, session hijacking, or exfiltration of authenticated API responses.

Recommendations Update to version 3.18.1.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-42548

GHSA-FCX8-PH5R-MXR4

Affected Products

Flight

References · 6

• 🔥 https://github.com/flightphp/core/security/advisories/GHSA-fcx8-ph5r-mxr4 · Exploit
• https://osv.dev/vulnerability/GHSA-fcx8-ph5r-mxr4 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-42548 · Security Note
• https://github.com/flightphp/core · Note
• https://twitter.com/CVEnew/status/2054709247024435404 · Twitter Post
• https://t.me/CVEtracker/53694 · Telegram Post