Cross-Site Scripting (XSS) in OpenProject (CVE-2026-52781)
Summary
Cross-site scripting in OpenProject (CVE-2026-52781). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 17.3.3 or later.
Original description
The description as published by the source.
OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, the HTML sanitizer grants elements unrestricted data-* attributes via :data wildcard. An attacker injects data-controller="poll-for-changes" into a work package description, causing Stimulus.js to mount a controller that fetches an attacker-uploaded attachment and passes it to renderStreamMessage(). This executes arbitrary Turbo Stream actions — including redirect_to — in every victim's authenticated browser session, redirecting them to an attacker-controlled server. This vulnerability is fixed in 17.3.3 and 17.4.1.
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-2026-52781 has been found in OpenProject.
Risk of unauthorized operations or information disclosure. CVSS score: 6.4/10.
What to do: upgrade OpenProject to 17.3.3 or later.
If unsure, ask your IT team or search "OpenProject CVE-2026-52781" on the vendor's site.
CVE-2026-52781 (OpenProject) — CWE-79 / CVSS v3 6.4
Attack vector: remote (network-reachable) / no user interaction
Patched: 17.3.3 — 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 OpenProject.
Check the vendor advisory for the affected versions of OpenProject.
Severity: Medium (CVSS 6.4/10). Risk of unauthorized operations or information disclosure.
Update to 17.3.3.
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 'OpenProject' . 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 'OpenProject' . | 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
OpenProject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 OpenProject to 17.3.3ステージング環境で 17.3.3 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