CVE-2021-20835

Name: CVE-2021-20835
Creator: NVD / NIST
Published: 2021-11-24T16:15:12.97+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.33%

Last modified Jun 17, 2026

CVE-2021-20835 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Improper authorization in handler for custom URL scheme vulnerability in Android App 'Mercari (Merpay) - Marketplace and Mobile Payments App' (Japan version) versions prior to 4.49.1 allows a remote attacker to lead a user to access an arbitrary website and the website launches an arbitrary Activity of the app via the vulnerable App, which may result in Mercari account's access token being obtained.. EPSS estimates a 1.33% chance of exploitation in the next 30 days.

Description

Improper authorization in handler for custom URL scheme vulnerability in Android App 'Mercari (Merpay) - Marketplace and Mobile Payments App' (Japan version) versions prior to 4.49.1 allows a remote attacker to lead a user to access an arbitrary website and the website launches an arbitrary Activity of the app via the vulnerable App, which may result in Mercari account's access token being obtained.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.33%

67.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Mercari	Mercari	< 4.49.1

References

https://jvn.jp/en/jp/JVN49465877/index.htmlThird Party Advisory
https://jvn.jp/en/jp/JVN49465877/index.htmlThird Party Advisory

Timeline

Published: Nov 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20835?

How severe is CVE-2021-20835?

CVE-2021-20835 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.33% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20835?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-20835?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST