Cross-Site Scripting (XSS) in Mcgill (CVE-2026-35169)
Summary
Cross-site scripting in Mcgill (CVE-2026-35169). Confidential information can be exposed externally. Mitigation: upgrade to 27.0.3 or later.
Original description
The description as published by the source.
LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. From to before 27.0.3 and 28.0.1, the help_editor module of LORIS did not properly sanitize some user supplied variables which could result in a reflected cross-site scripting attack if a user is tricked into following an invalid link. The same input vector could also allow an attacker to download arbitrary markdown files on an unpatched server. This vulnerability is fixed in 27.0.3 and 28.0.1.
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-2026-35169 has been found in Mcgill.
Confidential information can be exposed externally. CVSS score: 8.7/10.
What to do: upgrade Mcgill to 27.0.3 or later.
If unsure, ask your IT team or search "Mcgill CVE-2026-35169" on the vendor's site.
CVE-2026-35169 (Mcgill) — CWE-79 / CVSS v3 8.7
Attack vector: remote (network-reachable)
Patched: 27.0.3 — 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 Mcgill.
Check the vendor advisory for the affected versions of Mcgill.
Severity: High (CVSS 8.7/10). Confidential information can be exposed externally.
Update to 27.0.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Mcgill' . 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
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1Identify exposure identify
grep -r 'Mcgill' . | 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
Mcgillを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Mcgill to 27.0.3ステージング環境で 27.0.3 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を含めること。
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3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov