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CVE-2026-46428
Vulnerability in lettre (CVE-2026-46428)
Summary
vulnerability in lettre (CVE-2026-46428). Risk of unauthorized operations or information disclosure. Exploitable via ``rustls``. Mitigation: upgrade to `0.11.22` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-46428** has been found in lettre.
Attackers can target a specific entry point like ``rustls`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade lettre to **0.11.22** or later.
If unsure, ask your IT team or search "lettre CVE-2026-46428" on the vendor's site.
CVE-2026-46428 (lettre) — CWE-295 /
Attack surface: `rustls` / `true` / `false` / `TlsParametersBuilder`
Patched: `0.11.22` — 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** (CWE-295) exists in lettre. Attackers reach the vulnerable code path via ``rustls`` without authentication.
📍 Affected scope
lettre — . Attack surface: `rustls` / `true` / `false` / `TlsParametersBuilder`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **0.11.22**.
🛡️ 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 'lettre' .` 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
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1Identify exposure identify
grep -r 'lettre' . | 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 `lettre` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade lettre to 0.11.22ステージング環境で 0.11.22 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。
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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
rust
lettre
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.22"}]}]
References
- web https://github.com/lettre/lettre/commit/f5efffc88360dbdbfcef80f465e42d5bce68ca35
- web https://github.com/lettre/lettre/releases/tag/v0.11.22
- web https://github.com/lettre/lettre/security/advisories/GHSA-4pj9-g833-qx53
- web https://rustsec.org/advisories/RUSTSEC-2026-0141.html
- web https://nvd.nist.gov/vuln/detail/CVE-2026-46428
- web https://github.com/advisories/GHSA-4pj9-g833-qx53