CVE-2021-32816

Name: CVE-2021-32816
Creator: NVD / NIST
Published: 2021-05-14T18:15:07.407+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.01%

Last modified Jun 17, 2026

CVE-2021-32816 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. ProtonMail Web Client is the official AngularJS web client for the ProtonMail secure email service. ProtonMail Web Client before version 3.16.60 has a regular expression denial-of-service vulnerability. EPSS estimates a 1.01% chance of exploitation in the next 30 days.

Description

ProtonMail Web Client is the official AngularJS web client for the ProtonMail secure email service. ProtonMail Web Client before version 3.16.60 has a regular expression denial-of-service vulnerability. This was fixed in commit 6687fb. There is a full report available in the referenced GHSL-2021-027.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.01%

58.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Protonmail	Protonmail	< 3.16.60

References

https://github.com/ProtonMail/WebClient/commit/6687fbb867ef872c96cf4fde68cb6e9c58d3fddcPatch, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2021-027-redos-ProtonMail/Exploit, Third Party Advisory
https://github.com/ProtonMail/WebClient/commit/6687fbb867ef872c96cf4fde68cb6e9c58d3fddcPatch, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2021-027-redos-ProtonMail/Exploit, Third Party Advisory

Timeline

Published: May 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32816?

How severe is CVE-2021-32816?

CVE-2021-32816 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.01% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32816?

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-2021-32816?

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

Scan your code now

Source: NVD / NIST