← Back
DEBIAN-CVE-2026-4689
Vulnerability in firefox-esr (DEBIAN-CVE-2026-4689)
Summary
vulnerability in firefox-esr (DEBIAN-CVE-2026-4689). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to `140.9.0esr-1~deb11u1` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **DEBIAN-CVE-2026-4689** has been found in firefox-esr.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade firefox-esr to **140.9.0esr-1~deb11u1** or later.
If unsure, ask your IT team or search "firefox-esr DEBIAN-CVE-2026-4689" on the vendor's site.
DEBIAN-CVE-2026-4689 (firefox-esr) —
Patched: `140.9.0esr-1~deb11u1` — 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 firefox-esr.
📍 Affected scope
firefox-esr — .
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **140.9.0esr-1~deb11u1**.
🛡️ 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 'firefox-esr' .` 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
-
1Identify exposure identify
grep -r 'firefox-esr' . | 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 `firefox-esr` を grep し、稼働しているサービス・バージョンを把握する。
-
6Apply patch patch
Upgrade firefox-esr to 140.9.0esr-1~deb11u1ステージング環境で 140.9.0esr-1~deb11u1 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。
-
7Post-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
Debian:11
firefox-esr
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"140.9.0esr-1~deb11u1"}]}]
Debian:12
firefox-esr
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"140.9.0esr-1~deb12u1"}]}]
Debian:13
firefox-esr
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"140.9.0esr-1~deb13u1"}]}]
Debian:14
firefox-esr
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"140.9.0esr-1"}]}]
Debian:11
thunderbird
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:140.9.0esr-1~deb11u1"}]}]
Debian:12
thunderbird
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:140.9.0esr-1~deb12u1"}]}]
Debian:13
thunderbird
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:140.9.0esr-1~deb13u1"}]}]
Debian:14
thunderbird
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:140.9.0esr-1"}]}]