Path Traversal in penelope-shell-handler (CVE-2026-50558)
Summary
Path traversal in penelope-shell-handler (CVE-2026-50558). Data can be tampered with by attackers. Exploitable via download. Mitigation: upgrade to 0.20.0 or later.
Original description
The description as published by the source.
Summary
Penelope versions prior to 0.19.3 extracted tar archives received from remote sessions without validating archive member paths. When using the affected Unix download path, a malicious or compromised remote session could return a crafted tar archive containing path traversal entries, such as ../, causing files to be written outside the intended download directory on the Penelope operator's machine.
The impact is limited to files writable by the user running Penelope. In some cases, this arbitrary file write could be chained to operator-side code execution if the attacker can overwrite a file that Penelope or the user later executes, such as ~/.penelope/peneloperc. The issue has been fixed in version 0.19.3 by rejecting unsafe archive paths during extraction.
Affected conditions
The issue requires the operator to use the Main Menu download command to download files from a malicious or compromised remote session that can influence the tar archive returned to Penelope. The Python agent download path is not affected in the same way because it does not rely on the remote tar command.
The vulnerable behavior is related to Python's historical tarfile extraction defaults. In Python versions before 3.14, TarFile.extractall() did not use the safer data extraction filter by default, so applications extracting untrusted tar archives needed to explicitly provide a safe extraction filter or perform their own path validation.
Python 3.14 changes the defaul…
Source: GitHub Security Advisories (Global) 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-2026-50558 has been found in penelope-shell-handler.
Attackers can target a specific entry point like download over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 5.9/10.
What to do: upgrade penelope-shell-handler to 0.20.0 or later.
If unsure, ask your IT team or search "penelope-shell-handler CVE-2026-50558" on the vendor's site.
CVE-2026-50558 (penelope-shell-handler) — CWE-22 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: download / tar / tarfile / data
Patched: 0.20.0 — 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.
Path traversal (CWE-22) exists in penelope-shell-handler. Attackers reach the vulnerable code path via download without authentication.
Check the vendor advisory for the affected versions of penelope-shell-handler. Attack surface: download / tar / tarfile / data.
Severity: Medium (CVSS 5.9/10). Data can be tampered with by attackers.
Update to 0.20.0.
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 'penelope-shell-handler' . 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 'penelope-shell-handler' . | 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
penelope-shell-handler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 penelope-shell-handler to 0.20.0ステージング環境で 0.20.0 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 github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com