Critical Input validation

CVE-2026-53513 — Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the @better-auth/sso plugin's POST /sso/register and POST /sso/update-provider endpoints accept attacker-controlled oidcConfig.userInfoEndpoint, tokenEndpoint, and jwksEndpoint URLs when skipDiscovery: true is set, store them on the ssoProvider row without origin validation, and fetch them during OIDC callback, allowing non-blind server-side request forgery and possible account linking when trustEmailVerified: true is configured. This issue is fixed in version 1.6.11.

Published Jul 15, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Better-auth

Better-auth and 1 more

CVSS base

9.6

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented patch — github.com (NIST National Vulnerability Database)
Documented mitigation — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Better-auth Better-auth, Better-auth Sso).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (input validation), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Better-auth	Better-auth	≥ 0.1.0 and < 1.6.11	Vulnerable	NIST National Vulnerability Database
Better-auth	Better-auth	version >= 0.1.0, < 1.6.11	Vulnerable	CVE Program (cve.org) e CISA ADP
Better-auth	Sso	< 1.6.11	Vulnerable	NIST National Vulnerability Database
Better-auth	Sso	version >= 0.1.0, < 1.6.11	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.6	CVSS 3.1	Critical	3.1	5.8	security-advisories@github.com via NIST National Vulnerability Database
9.6	CVSS 3.1	Critical	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-20 · Improper Input Validation

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · better-auth/better-auth, @better-auth/sso
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 9.6
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 15, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

4 on the record

github.com/better-auth/better-auth/security/advisories/GHSA-5rr4-8452-hf4v
Mitigation, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
github.com/better-auth/better-auth/commit/37f60cb176cb53147da7dfd5ec15afa5b486e8
Patch, x_refsource_MISC, NIST National Vulnerability Database
github.com/better-auth/better-auth/pull/9574
Issue Tracking, Patch, x_refsource_MISC, NIST National Vulnerability Database
github.com/better-auth/better-auth/releases/tag/v1.6.11
Release Notes, x_refsource_MISC, NIST National Vulnerability Database

Elsewhere on this site

Better-auth
every CVE for this vendor

Input validation
same class

CWE-20
other pages naming this weakness

Related CVEs (same products)

Low CVE-2026-110861 Better Auth drizzle-adapter 1.6.17 before 1.7.7 Rate Limit Bypass via Race Condition 1d
High CVE-2026-110864 Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy 1d
Critical CVE-2026-110862 Better Auth 1.4.0-beta.18 before 1.7.7 Authentication Bypass via Magic Link 1d
High CVE-2026-110863 Better Auth @better-auth/sso before 1.7.3 Authentication Bypass via Personal SSO Providers 1d
High CVE-2026-109346 better-auth 1.3.8-beta.3 before 1.7.0-rc.3 Device Authorization Phishing via /device 3d
High CVE-2026-80192 better-auth SSO before 1.6.27 Domain Ownership Authentication Bypass Aug 26, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-53513 is "Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration", rated Critical. It affects Better-auth (Better-auth); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.6 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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