Cross-Site Scripting (XSS) in flightphp/core (CVE-2026-42548)
Summary
Cross-site scripting in flightphp/core (CVE-2026-42548). Risk of unauthorized operations or information disclosure. Exploitable via GET /api. Mitigation: upgrade to 3.18.1 or later.
Original description
The description as published by the source.
Flight is an extensible micro-framework for PHP. Prior to 3.18.1, Flight::jsonp() concatenates the ?jsonp= query parameter directly into an application/javascript response body without validating that the value is a legal JavaScript identifier. An attacker can inject arbitrary JavaScript that executes in the response origin, enabling reflected cross-site scripting. This vulnerability is fixed in 3.18.1.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-42548 has been found in flightphp/core.
Attackers can target a specific entry point like GET /api over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade flightphp/core to 3.18.1 or later.
If unsure, ask your IT team or search "flightphp/core CVE-2026-42548" on the vendor's site.
CVE-2026-42548 (flightphp/core) — CWE-79
Attack surface: GET /api / victim.tld / b8dd23a / jsonp
Patched: 3.18.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in flightphp/core. Attackers reach the vulnerable code path via GET /api.
Check the vendor advisory for the affected versions of flightphp/core. Attack surface: GET /api / victim.tld / b8dd23a / jsonp.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 3.18.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api requests with malformed payloads or SQL meta-characters. Run grep -r 'flightphp/core' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'flightphp/core' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
flightphp/coreを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /api' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /apiへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade flightphp/core to 3.18.1ステージング環境で 3.18.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against GET /api on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com