Vulnerability in tomcat9 (USN-8417-1)

Summary

vulnerability in tomcat9 (USN-8417-1). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to `9.0.16-3ubuntu0.18.04.2+esm8` or later.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **USN-8417-1** has been found in tomcat9. Risk of unauthorized operations or information disclosure. CVSS score: ?/10. What to do: upgrade tomcat9 to **9.0.16-3ubuntu0.18.04.2+esm8** or later. If unsure, ask your IT team or search "tomcat9 USN-8417-1" on the vendor's site.

USN-8417-1 (tomcat9) — Patched: `9.0.16-3ubuntu0.18.04.2+esm8` — 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

**A vulnerability** (unclassified) exists in tomcat9.

📍 Affected scope

tomcat9 — .

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure

🔧 How to fix

Update to **9.0.16-3ubuntu0.18.04.2+esm8**.

🛡️ 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 request patterns matching this CVE's known IOCs. Run `grep -r 'tomcat9' .` 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
Identify exposure identify
```
grep -r 'tomcat9' . | 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 `tomcat9` を grep し、稼働しているサービス・バージョンを把握する。
6
Apply patch patch
```
Upgrade tomcat9 to 9.0.16-3ubuntu0.18.04.2+esm8
```
ステージング環境で 9.0.16-3ubuntu0.18.04.2+esm8 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。
7
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 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

Ubuntu:Pro:18.04:LTS tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.16-3ubuntu0.18.04.2+esm8"}]}]

Ubuntu:Pro:20.04:LTS tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.31-1ubuntu0.9+esm3"}]}]

Ubuntu:Pro:22.04:LTS tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.58-1ubuntu0.2+esm4"}]}]

Ubuntu:Pro:24.04:LTS tomcat10

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.1.16-1ubuntu0.1~esm4"}]}]

Ubuntu:Pro:24.04:LTS tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.70-2ubuntu0.1+esm3"}]}]

Ubuntu:25.10 tomcat10

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.1.40-1ubuntu1.25.10.1"}]}]

Ubuntu:25.10 tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.95-1ubuntu1.1"}]}]

Ubuntu:26.04:LTS tomcat10

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.1.40-1ubuntu1.26.04.1"}]}]

Ubuntu:26.04:LTS tomcat9

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.0.115-1ubuntu0.1"}]}]

References

advisory https://ubuntu.com/security/notices/USN-8417-1
report https://ubuntu.com/security/CVE-2026-41284
report https://ubuntu.com/security/CVE-2026-41293
report https://ubuntu.com/security/CVE-2026-42498
report https://ubuntu.com/security/CVE-2026-43512
report https://ubuntu.com/security/CVE-2026-43513
report https://ubuntu.com/security/CVE-2026-43515