Vulnerability in Webmail (CVE-2026-35391)
Summary
Vulnerability in Webmail (CVE-2026-35391). Data can be tampered with by attackers. Mitigation: upgrade to 1.4.11 or later.
Original description
The description as published by the source.
Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, the getClientIP() function in lib/admin/session.ts trusted the first (leftmost) entry of the X-Forwarded-For header, which is fully controlled by the client. An attacker could forge their source IP address to bypass IP-based rate limiting (enabling brute-force attacks against the admin login) or forge audit log entries (making malicious activity appear to originate from arbitrary IP addresses). This vulnerability is fixed in 1.4.11.
Source: NIST National Vulnerability Database NVD
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-2026-35391 has been found in Webmail.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: upgrade Webmail to 1.4.11 or later.
If unsure, ask your IT team or search "Webmail CVE-2026-35391" on the vendor's site.
CVE-2026-35391 (Webmail) — CWE-348 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.4.11 — 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-348) exists in Webmail.
Check the vendor advisory for the affected versions of Webmail.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to 1.4.11.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Webmail' . 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
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1Identify exposure identify
grep -r 'Webmail' . | 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
Webmailを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Webmail to 1.4.11ステージング環境で 1.4.11 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。
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3Post-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。