CVE-2026-65829 medium CVSS 5.3

Path Traversal in MPXJ.Net (CVE-2026-65829)

Summary

Path traversal in MPXJ.Net (CVE-2026-65829). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 16.5.0 or later.

Original description

The description as published by the source.

Impact

When reading a suitably crafted PRX or STX file, MPXJ can be made to write files to arbitrary locations in the file system.

Patches

This issue is addressed in MPXJ version 16.5.0.

Workarounds

Do not read PRX or STX files from untrusted sources.

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-2026-65829 has been found in MPXJ.Net.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade MPXJ.Net to 16.5.0 or later.
If unsure, ask your IT team or search "MPXJ.Net CVE-2026-65829" on the vendor's site.

CVE-2026-65829 (MPXJ.Net) — CWE-22 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 16.5.0 — apply immediately
Workaround: Do not read PRX or STX files from untrusted sources.
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.

❓ What is the problem

Path traversal (CWE-22) exists in MPXJ.Net.

📍 Affected scope

Check the vendor advisory for the affected versions of MPXJ.Net.

🔥 Severity

Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 16.5.0.

🛡️ Workaround

Workaround: Do not read PRX or STX files from untrusted sources.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'MPXJ.Net' . 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

1
Identify exposure identify
```
grep -r 'MPXJ.Net' . | 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 MPXJ.Net を grep し、稼働しているサービス・バージョンを把握する。
2
Apply temporary workaround mitigate
```
Do not read PRX or STX files from untrusted sources.
```
パッチが適用されるまでの応急処置として、Do not read PRX or STX files from untrusted sources. を実施。回避策の副作用 (機能低下) を確認した上で。
3
Apply patch patch
```
Upgrade MPXJ.Net to 16.5.0
```
ステージング環境で 16.5.0 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。
4
Post-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。