Malcolm is a network traffic analysis tool suite. The file-upload component (FilePond PHP backend) accepts uploads at…
Summary
Vulnerability reported (CVE-2026-55676). Successful exploitation can lead to full system takeover. Exploitable via POST /server/php/submit.php.
Original description
The description as published by the source.
Malcolm is a network traffic analysis tool suite. The file-upload component (FilePond PHP backend) accepts uploads at POST /server/php/submit.php and stores them in a directory served by the same nginx and php-fpm instance. The allow-list that should restrict accepted file types is an empty array by default (file-upload/php/config.php:16), so the type check is a no-op and every extension is accepted. The filename sanitizer keeps the .php extension intact. Committed files land in /var/www/upload/server/php/files (file-upload/php/config.php:7), and the component's nginx routes any URL ending in .php to php-fpm. An authenticated GET /server/php/files/.php then executes the uploaded code as www-data. Prior to version 26.06.1, in RBAC mode, the upload endpoint is reachable by the granular ROLE_UPLOAD role (nginx/lua/nginx_auth_helpers.lua:71), a role intended only for submitting capture files. As a result, a user holding the upload-only role runs arbitrary PHP as www-data inside the file-upload container. Version 26.06.1 fixes the issue.
Source: NIST National Vulnerability Database NVD
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-2026-55676 has been found.
Attackers can target a specific entry point like POST /server/php/submit.php over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2026-55676" on the vendor's site.
CVE-2026-55676 — CWE-434 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /server/php/submit.php / GET /server/php/files/ / ROLE_UPLOAD
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.
A vulnerability (CWE-434) has been reported. Attackers reach the vulnerable code path via POST /server/php/submit.php.
Check the vendor advisory for the affected versions. Attack surface: POST /server/php/submit.php / GET /server/php/files/ / ROLE_UPLOAD.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
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 POST /server/php/submit.php requests with malformed payloads or SQL meta-characters. Audit SBOM/dependencies 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
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
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2Hunt for indicators of compromise detect
grep 'POST /server/php/submit.php' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /server/php/submit.php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。 -
3Post-deployment verification verify
Replay attack against POST /server/php/submit.php 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。
References
- web ics-cert@hq.dhs.gov
- web ics-cert@hq.dhs.gov
- web ics-cert@hq.dhs.gov
- web ics-cert@hq.dhs.gov