Cross-Site Scripting (XSS) in @haxtheweb/haxcms-nodejs (CVE-2026-48527)
Summary
Cross-site scripting in @haxtheweb/haxcms-nodejs (CVE-2026-48527). Confidential information can be exposed externally. Exploitable via POST /system/api/saveNode. Mitigation: upgrade to 26.0.1 or later.
Original description
The description as published by the source.
Summary
HaxCMS is affected by a stored cross-site scripting (XSS) vulnerability in the /system/api/saveNode endpoint. An authenticated user with a permission to edit pages can bypass the HTML sanitizer by injecting an event handler attribute without whitespace before the attribute name.
For example, the sanitizer misses:
click me
The important bypass is:
href="#"onclick=
The payload is stored in the generated page files and executes when a user clicks the injected link.
Details
The issue is caused by regex-based HTML sanitization that expects whitespace before event handler attributes. Because the sanitizer expects a pattern like:
href="#" onclick="..."
It fails to remove an event handler when it is written without whitespace:
href="#"onclick="..."
Browsers still parse onclick as a valid event handler attribute, so the JavaScript executes when the element is clicked.
Affected endpoint:
POST /system/api/saveNode?site_token=[VALID_SITE_TOKEN]
Affected parameter:
node.body
PoC
-
Log in to HaxCMS and edit any existing page.
-
Capture the page save request in Burp Suite:
POST /system/api/saveNode?site_token=[VALID_SITE_TOKEN]
- In the JSON request body, modify only the
node.bodyvalue.
Change:
"body":"...existing page content...\n"
To:
"body":"...existing page content...\nclick me\n"
-
Forward the request.
-
Open the edited page and…
Source: GitHub Security Advisories (Global) 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-2026-48527 has been found in @haxtheweb/haxcms-nodejs.
Attackers can target a specific entry point like POST /system/api/saveNode over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.7/10.
What to do: upgrade @haxtheweb/haxcms-nodejs to 26.0.1 or later.
If unsure, ask your IT team or search "@haxtheweb/haxcms-nodejs CVE-2026-48527" on the vendor's site.
CVE-2026-48527 (@haxtheweb/haxcms-nodejs) — CWE-79 / CVSS v3 8.7
Attack vector: remote (network-reachable)
Attack surface: POST /system/api/saveNode / onclick / node.body / index.html
Patched: 26.0.1 — 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 @haxtheweb/haxcms-nodejs. Attackers reach the vulnerable code path via POST /system/api/saveNode.
Check the vendor advisory for the affected versions of @haxtheweb/haxcms-nodejs. Attack surface: POST /system/api/saveNode / onclick / node.body / index.html.
Severity: High (CVSS 8.7/10). Confidential information can be exposed externally.
Update to 26.0.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /system/api/saveNode requests with malformed payloads or SQL meta-characters. Run grep -r '@haxtheweb/haxcms-nodejs' . 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 '@haxtheweb/haxcms-nodejs' . | 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
@haxtheweb/haxcms-nodejs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 'POST /system/api/saveNode' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /system/api/saveNode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 @haxtheweb/haxcms-nodejs to 26.0.1ステージング環境で 26.0.1 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 POST /system/api/saveNode 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 nvd.nist.gov
- package github.com
- web github.com
- web github.com