How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

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357,869

Total vulnerabilities in the database

CVE-2026-45337 — better-auth

Improper Authorization

Am I affected?

You are affected if all of the following are true:

You use better-auth at a version >= 1.6.0, < 1.6.11.
The deviceAuthorization plugin is enabled in your auth config (deviceAuthorization() in your plugins array).
A third party can observe a pending user code before the legitimate user completes verification.

The standard device-flow UX displays user codes to humans, so realistic exposure includes shoulder-surfing, screen-share, voice or video calls, support-chat transcripts, referrer headers, and shared logs.

If your application does not enable the deviceAuthorization plugin, you are not affected.

Fix:

Upgrade to [email protected] or later.
If you cannot upgrade, see workarounds below.

Summary

Better Auth's deviceAuthorization plugin treated any authenticated session as the owner of any pending device code. The ownership gate on POST /device/approve and POST /device/deny short-circuited whenever the row's userId was unset, and the GET /device verification handler did not claim the row. An authenticated attacker who learned a valid user_code before the legitimate user completed approval could bind the polling device to the attacker's account or deny the legitimate flow.

Details

The device authorization flow binds the polling device to the user who entered the user code on the verification page. In affected versions, the plugin only created that binding at approve or deny time, with no claim at the verification step. The ownership check at approve and deny short-circuited when the owner was missing, accepting any authenticated caller instead of rejecting the request.

The fix changes GET /device to claim the pending row for the calling session. The approve and deny gates now require strict equality between the row's owner and the calling session. RFC 8628 §5.5 covers this risk class as Session Spying: a malicious party can hijack a session by completing authorization before the legitimate initiating user does.

Patches

Fixed in [email protected]. After the patch, GET /device claims the pending row for the calling session, and POST /device/approve and POST /device/deny reject calls whose session does not match the claimed owner. Custom verification pages must serve GET /device to an authenticated session for the flow to succeed.

Workarounds

If you cannot upgrade immediately:

Disable the plugin if you do not use the device flow: remove deviceAuthorization() from your plugins array.
Add a before hook on POST /device/approve and POST /device/deny that tracks which session called GET /device for each user code, and rejects calls from a different session.
Shorten the pending lifetime of device codes via the expiresIn plugin option to reduce the exploitation window.

Impact

Account takeover on the polling device: the attacker's session becomes the device's session, so the device operates as the attacker.
Denial of the legitimate sign-in: the attacker can mark the code as denied, blocking the victim's flow.

Credit

Reported by Quikturn Security Team.

Published: Jun 4, 2026
Updated: Jun 5, 2026
CVE: CVE-2026-45337
GHSA: GHSA-cq3f-vc6p-68fh
Severity: High
Exploit:
CISA KEV:

CVSS v3:

Severity: High
Score: 7.6
AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L

CWEs:

OWASP TOP 10:

A5 - Broken Access Control

Affected Software
References

Software	From	Fixed in
better-auth	1.6.0	1.6.11

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.