CVE-2026-109346 (CVSS 8.1)

Description

better-auth from 1.3.8-beta.3 before 1.7.0-rc.3 contains a UI misrepresentation vulnerability in the deviceAuthorization plugin because GET /device omits the requesting client_id and scope. Attackers can start a device request via /device/code, trick signed-in users into approving the code, then redeem it at /device/token for a live session token.

Is your site exposed to CVE-2026-109346?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0028

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-451 CWE-451

References

Other References

https://github.com/better-auth/better-auth/security/advisories/GHSA-q84f-53jg-9ppm https://www.vulncheck.com/advisories/better-auth-1.3.8-beta.3-before-1.7.0-rc.3-device-authorization-phishing-via-device

Frequently Asked Questions

What is CVE-2026-109346? +

better-auth from 1.3.8-beta.3 before 1.7.0-rc.3 contains a UI misrepresentation vulnerability in the deviceAuthorization plugin because GET /device omits the requesting client_id and scope. Attackers can start a device request via /device/code, trick signed-in users into approving the code, then redeem it at /device/token for a live session token. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-109346? +

CVE-2026-109346 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0028, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-109346? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-45150

Zen is a firefox-based browser. Prior to 1.19.13b, Zen Browser did not provide a persistent, clearly visible security notification when …

CVE-2024-52277

User Interface (UI) Misrepresentation of Critical Information vulnerability in DocuSeal allows Content Spoofing.Displayed version does not show the layer flattened …

CVE-2024-52270

User Interface (UI) Misrepresentation of Critical Information vulnerability in DropBox Sign(HelloSign) allows Content Spoofing. Displayed version does not show the …

CVE-2024-52271

User Interface (UI) Misrepresentation of Critical Information vulnerability in Documenso allows Content Spoofing.Displayed version does not show the layer flattened …

CVE-2026-84356

UI misrepresentation in FullScreen in Google Chrome prior to 152.0.7977.75 allowed a remote attacker to spoof address bar via a …

CVE-2026-84330

UI misrepresentation in FullScreen in Google Chrome on on Android prior to 152.0.7977.75 allowed a remote attacker to spoof address …

CVE-2026-109346