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CVE-2026-62323 medium CVSS 6.3

Authorization Flaw in github.com/cloudreve/Cloudreve/v4 (CVE-2026-62323)

Summary

vulnerability in github.com/cloudreve/Cloudreve/v4 (CVE-2026-62323). Data can be tampered with by attackers. Exploitable via `PUT /api/v4/file/viewerSession`. Mitigation: upgrade to `4.0.0-20260626022433-f3347130ac48` or later.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **CVE-2026-62323** has been found in github.com/cloudreve/Cloudreve/v4. Attackers can target a specific entry point like `PUT /api/v4/file/viewerSession` over the network to misuse the product. Data can be tampered with by attackers. CVSS score: 6.3/10. What to do: upgrade github.com/cloudreve/Cloudreve/v4 to **4.0.0-20260626022433-f3347130ac48** or later. If unsure, ask your IT team or search "github.com/cloudreve/Cloudreve/v4 CVE-2026-62323" on the vendor's site.
CVE-2026-62323 (github.com/cloudreve/Cloudreve/v4) — CWE-863 / CVSS v3 6.3 Attack vector: remote (network-reachable) Attack surface: PUT /api/v4/file/viewerSession / GET /api/v4/file/wopi/4xc5 / GET /api/v4/file/wopi/4xc5/contents / POST /api/v4/file/wopi/4xc5/contents Patched: `4.0.0-20260626022433-f3347130ac48` — 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.
❓ What is the problem
**incorrect authorization** (CWE-863) exists in github.com/cloudreve/Cloudreve/v4. Attackers reach the vulnerable code path via `PUT /api/v4/file/viewerSession` without authentication.
📍 Affected scope
github.com/cloudreve/Cloudreve/v4 — . Attack surface: PUT /api/v4/file/viewerSession / GET /api/v4/file/wopi/4xc5 / GET /api/v4/file/wopi/4xc5/contents / POST /api/v4/file/wopi/4xc5/contents.
🔥 Severity
Severity: Medium (CVSS 6.3/10). Data can be tampered with by attackers
🔧 How to fix
Update to **4.0.0-20260626022433-f3347130ac48**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual `PUT /api/v4/file/viewerSession` requests with malformed payloads or SQL meta-characters. Run `grep -r 'github.com/cloudreve/Cloudreve/v4' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response Actions (7 steps)

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    grep -r 'github.com/cloudreve/Cloudreve/v4' . | 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 `github.com/cloudreve/Cloudreve/v4` を grep し、稼働しているサービス・バージョンを把握する。

  2. 3
    Hunt for indicators of compromise detect
    grep 'PUT /api/v4/file/viewerSession' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで `PUT /api/v4/file/viewerSession` 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。

  3. 6
    Apply patch patch
    Upgrade github.com/cloudreve/Cloudreve/v4 to 4.0.0-20260626022433-f3347130ac48

    ステージング環境で 4.0.0-20260626022433-f3347130ac48 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 3 で見つけた異常検知の続報チェックを含めること。

  4. 7
    Post-deployment verification verify
    Replay attack against PUT /api/v4/file/viewerSession 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 3 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

go github.com/cloudreve/Cloudreve/v4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-20260626022433-f3347130ac48"}]}]
go github.com/cloudreve/Cloudreve/v3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

References

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