Vulnerability in openmage/magento-lts (CVE-2026-42155)
Summary
Vulnerability in openmage/magento-lts (CVE-2026-42155). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/xmlrpc/. Mitigation: upgrade to 20.18.0 or later.
Original description
The description as published by the source.
Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to 20.18.0, the XML-RPC / SOAP API session ID is generated using an outdated, time-based construction rather than a Cryptographically Secure Pseudo-Random Number Generator (CSPRNG). All inputs to the MD5 hash are time-derived and non-secure. Because the resulting digest relies entirely on the timestamp and the PHP internal LCG state, the effective entropy is severely constrained. This violates the OWASP ASVS v4 requirement of ≥ 64 bits of entropy (V3.2.2) and NIST SP 800-63B standards. By narrowing the LCG window (via server state leaks or general predictability) and leveraging the lack of API rate-limiting, an attacker can generate a localized pool of candidate MD5 hashes and execute a high-speed online brute-force attack to hijack active API sessions. This vulnerability is fixed in 20.18.0.
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-2026-42155 has been found in openmage/magento-lts.
Attackers can target a specific entry point like POST /api/xmlrpc/ over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade openmage/magento-lts to 20.18.0 or later.
If unsure, ask your IT team or search "openmage/magento-lts CVE-2026-42155" on the vendor's site.
CVE-2026-42155 (openmage/magento-lts) — CWE-330
Attack surface: POST /api/xmlrpc/ / null / customer.list / customer.info
Patched: 20.18.0 — 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.
A vulnerability (CWE-330) exists in openmage/magento-lts. Attackers reach the vulnerable code path via POST /api/xmlrpc/.
Check the vendor advisory for the affected versions of openmage/magento-lts. Attack surface: POST /api/xmlrpc/ / null / customer.list / customer.info.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 20.18.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/xmlrpc/ requests with malformed payloads or SQL meta-characters. Run grep -r 'openmage/magento-lts' . 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 'openmage/magento-lts' . | 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
openmage/magento-ltsを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/xmlrpc/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/xmlrpc/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。 -
3Apply patch patch
Upgrade openmage/magento-lts to 20.18.0ステージング環境で 20.18.0 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と、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /api/xmlrpc/ 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。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com