Cross-Site Scripting (XSS) in changedetection-io (CVE-2026-29038)
Summary
Cross-site scripting in changedetection-io (CVE-2026-29038). Risk of unauthorized operations or information disclosure. Exploitable via GET /rss/tag/. Mitigation: upgrade to 0.54.4 or later.
Original description
The description as published by the source.
A reflected cross-site scripting (XSS) vulnerability was identified in the /rss/tag/ endpoint of changedetection.io. The tag_uuid path parameter is reflected directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript.
This vulnerability persists in version 0.54.1, which patched the related XSS in /rss/watch/ (CVE-2026-27645 / GHSA-mw8m-398g-h89w) but did not address the identical pattern in the tag RSS endpoint.
Package
- Ecosystem: pip
- Package: changedetection.io
- Affected versions: <= 0.54.1
- Patched versions: (none yet)
Severity
Moderate - CVSS 6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Details
File: changedetectionio/blueprint/rss/tag.py Line: 36 Source: tag.py @ 1d72716
The tag_uuid parameter from the URL path is interpolated into the response body using an f-string with no escaping:
tag = datastore.data['settings']['application'].get('tags', {}).get(tag_uuid)
if not tag:
return f"Tag with UUID {tag_uuid} not found", 404 # ← No escaping, Content-Type: text/html
Flask's default Content-Type for plain string responses is text/html; charset=utf-8, so any HTML/JavaScript injected via {tag_uuid} is render…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2026-29038 has been found in changedetection-io.
Attackers can target a specific entry point like GET /rss/tag/ over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade changedetection-io to 0.54.4 or later.
If unsure, ask your IT team or search "changedetection-io CVE-2026-29038" on the vendor's site.
CVE-2026-29038 (changedetection-io) — CWE-79
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: GET /rss/tag/ / tag_uuid / single_watch.py / tag.py
Patched: 0.54.4 — 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 changedetection-io. Attackers reach the vulnerable code path via GET /rss/tag/ without authentication.
Check the vendor advisory for the affected versions of changedetection-io. Attack surface: GET /rss/tag/ / tag_uuid / single_watch.py / tag.py.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 0.54.4.
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 /rss/tag/ requests with malformed payloads or SQL meta-characters. Run grep -r 'changedetection-io' . 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 'changedetection-io' . | 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
changedetection-io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 /rss/tag/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /rss/tag/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 changedetection-io to 0.54.4ステージング環境で 0.54.4 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 /rss/tag/ 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
- web github.com
- web github.com