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CVE-2026-45364
high
CVSS 7.3
Vulnerability in better-auth (CVE-2026-45364)
Summary
vulnerability in better-auth (CVE-2026-45364). Risk of unauthorized operations or information disclosure. Exploitable via ``normalizeIP``. Mitigation: upgrade to `1.5.0-beta.9` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-45364** has been found in better-auth.
Attackers can target a specific entry point like ``normalizeIP`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.3/10.
What to do: upgrade better-auth to **1.5.0-beta.9** or later.
If unsure, ask your IT team or search "better-auth CVE-2026-45364" on the vendor's site.
CVE-2026-45364 (better-auth) — CWE-307 / CVSS v3 7.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `normalizeIP` / `getIp` / `onRequestRateLimit` / `advanced.ipAddress.ipv6Subnet`
Patched: `1.5.0-beta.9` — 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-307) exists in better-auth. Attackers reach the vulnerable code path via ``normalizeIP`` without authentication.
📍 Affected scope
better-auth — . Attack surface: `normalizeIP` / `getIp` / `onRequestRateLimit` / `advanced.ipAddress.ipv6Subnet`.
🔥 Severity
Severity: High (CVSS 7.3/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **1.5.0-beta.9**.
🛡️ 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 'better-auth' .` 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 'better-auth' . | 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 `better-auth` 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 better-auth to 1.5.0-beta.9ステージング環境で 1.5.0-beta.9 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
npm
better-auth
[{"type":"SEMVER","events":[{"introduced":"1.5.0-beta.1"},{"fixed":"1.5.0-beta.9"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-45364
- package https://github.com/better-auth/better-auth
- web https://github.com/better-auth/better-auth/security/advisories/GHSA-p6v2-xcpg-h6xw
- web https://github.com/better-auth/better-auth/pull/7470
- web https://github.com/better-auth/better-auth/pull/7509
- web https://github.com/better-auth/better-auth/commit/43e719bcc0c223c7079fa0c611a9cf7ea1188254
- web https://github.com/better-auth/better-auth/commit/57af0f7b910dcf7b1a5c0615d10b9bd56bb69bef
- web https://github.com/advisories/GHSA-p6v2-xcpg-h6xw