Authorization Flaw in Plastic Labs Honcho (CVE-2026-108711)
Summary
Vulnerability in Plastic Labs Honcho (CVE-2026-108711). Risk of unauthorized operations or information disclosure. Exploitable via POST /v3/workspaces.
Original description
The description as published by the source.
Plastic Labs Honcho through 3.3.0 contains an incorrect authorization vulnerability that allows peer- or session-scoped API key holders to read workspace data because get_or_create_workspace checks only the workspace claim. Attackers can submit their parent workspace name to the POST /v3/workspaces endpoint to retrieve workspace metadata and configuration, including custom_instructions, reserved for workspace or admin keys.
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-2026-108711 has been found in Plastic Labs Honcho.
Attackers can target a specific entry point like POST /v3/workspaces over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Plastic Labs Honcho CVE-2026-108711" on the vendor's site.
CVE-2026-108711 (Plastic Labs Honcho) — CWE-863 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /v3/workspaces
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.
Incorrect authorization (CWE-863) exists in Plastic Labs Honcho. Attackers reach the vulnerable code path via POST /v3/workspaces.
Check the vendor advisory for the affected versions of Plastic Labs Honcho. Attack surface: POST /v3/workspaces.
Severity: Medium (CVSS 4.3/10). 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 POST /v3/workspaces 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 Plastic Labs Honcho を使っているサービスとバージョンを洗い出す。
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2Hunt for indicators of compromise detect
grep 'POST /v3/workspaces' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /v3/workspaces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 /v3/workspaces 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。