Cross-Site Scripting (XSS) in copyparty (CVE-2026-30974)
Summary
Cross-site scripting in copyparty (CVE-2026-30974). Risk of unauthorized operations or information disclosure. Exploitable via nohtml. Mitigation: upgrade to 1.20.11 or later.
Original description
The description as published by the source.
Summary
The nohtml config option, intended to prevent execution of JavaScript in user-uploaded HTML files, did not apply to SVG images.
Details
A user with write-permission could upload an SVG containing embedded JavaScript, which would execute in the context of whichever user opens it.
This in itself is not a vulnerability; it is intended behavior according to the SVG spec. The vulnerability is that the nohtml volflag, when enabled, did not prevent this.
nohtml, intended for use on volumes which contains untrusted files, would correctly prevent execution of javascript in HTML files, but did not consider SVG images. This has been fixed in v1.20.11.
Impact
The malicious JavaScript could move or delete existing files on the server, or upload new files, using the account of the person who opens the SVG.
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-2026-30974 has been found in copyparty.
Attackers can target a specific entry point like nohtml over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade copyparty to 1.20.11 or later.
If unsure, ask your IT team or search "copyparty CVE-2026-30974" on the vendor's site.
CVE-2026-30974 (copyparty) — CWE-79
Attack vector: remote (network-reachable)
Attack surface: nohtml
Patched: 1.20.11 — 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 copyparty. Attackers reach the vulnerable code path via nohtml.
Check the vendor advisory for the affected versions of copyparty. Attack surface: nohtml.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.20.11.
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 'copyparty' . 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 'copyparty' . | 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
copyparty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 copyparty to 1.20.11ステージング環境で 1.20.11 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。
-
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。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com