Cross-Site Scripting (XSS) in wwbn/avideo (CVE-2026-41063)
Summary
Cross-site scripting in wwbn/avideo (CVE-2026-41063). Risk of unauthorized operations or information disclosure. Exploitable via ParsedownSafeWithLinks.
Original description
The description as published by the source.
Summary
The incomplete XSS fix in AVideo's ParsedownSafeWithLinks class overrides inlineMarkup for raw HTML but does not override inlineLink() or inlineUrlTag(), allowing javascript: URLs in markdown link syntax to bypass sanitization.
Affected Package
- Ecosystem: Other
- Package: AVideo
- Affected versions: < commit 3ae02fa24093
- Patched versions: >= commit 3ae02fa24093
Details
In objects/functionsSecurity.php, the ParsedownSafeWithLinks class:
- Overrides
blockMarkup()-- blocks non-/HTML tags - Overrides
inlineMarkup()-- sanitizesandin raw HTML, including an href whitelist
But the base Parsedown.php class has two additional methods that generate `` tags:
inlineLink()(line ~1388) -- processes[text](url)markdown syntax, setshref= URL directlyinlineUrlTag()(line ~1558) -- processes `` auto-link syntax, setshref= URL directly
Neither is overridden by ParsedownSafeWithLinks, so [Click me](javascript:alert(document.cookie)) produces Click me without any sanitization.
The fix sanitizes raw HTML tags via `inlineMarkup` but misses the markdown-native link syntax (`[text](url)`) and auto-link syntax () which produce `` tags through different code paths in the base Parsedown class.
PoC
"""
CVE-2026-33500 - Incomplete XSS fix in AVideo ParsedownSafeWithLinks
Tests REAL vulnerable code from:
objects/functionsSecurity.php (commit f154167, pre-fix 3ae02fa)
vendor…
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-2026-41063 has been found in wwbn/avideo.
Attackers can target a specific entry point like ParsedownSafeWithLinks over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "wwbn/avideo CVE-2026-41063" on the vendor's site.
CVE-2026-41063 (wwbn/avideo) — CWE-79
Attack vector: remote (network-reachable)
Attack surface: ParsedownSafeWithLinks / inlineMarkup / Parsedown.php / href
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 wwbn/avideo. Attackers reach the vulnerable code path via ParsedownSafeWithLinks.
Check the vendor advisory for the affected versions of wwbn/avideo. Attack surface: ParsedownSafeWithLinks / inlineMarkup / Parsedown.php / href.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
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 'wwbn/avideo' . 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 'wwbn/avideo' . | 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
wwbn/avideoを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com