Open Redirect in better-auth (CVE-2025-71403)
Summary
Vulnerability in better-auth (CVE-2025-71403). Data can be tampered with by attackers. Mitigation: upgrade to 1.1.21 or later.
Original description
The description as published by the source.
Summary
A bypass was discovered in the trustedOrigins validation logic—affecting both absolute URL entries and wildcard domain patterns. This flaw allows an attacker to construct a malicious callbackURL that passes origin checks and triggers an open redirect.
Because redirect endpoints include sensitive tokens (such as password-reset tokens), this vulnerability can enable one-click account takeover if a victim clicks a crafted link.
Source: NIST National Vulnerability Database NVD GitHub Advisory
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-2025-71403 has been found in better-auth.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: upgrade better-auth to 1.1.21 or later.
If unsure, ask your IT team or search "better-auth CVE-2025-71403" on the vendor's site.
CVE-2025-71403 (better-auth) — CWE-601 / CVSS v3 7.1
Attack vector: remote (network-reachable) / unauthenticated
Patched: 1.1.21 — 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-601) exists in better-auth.
Check the vendor advisory for the affected versions of better-auth.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to 1.1.21.
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 'better-auth' . 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 '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。 -
2Apply patch patch
Upgrade better-auth to 1.1.21ステージング環境で 1.1.21 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。
-
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。
Affected packages
References
- package github.com
- web disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web nvd.nist.gov
- web github.com
- web github.com
- web github.com