Regular expression Denial of Service in ProtonMail
Priority LOW 35CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-400.
Summary
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.
Why it matters now
EPSS 0.0101 63rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed WebClient (ProtonMail): 3.16.60
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ProtonMail | WebClient | before 3.16.60 | 3.16.60 | Patch available | CNA |
- WebClient VendorProtonMail Affected before 3.16.60 Fixed in 3.16.60 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:protonmail:protonmail:*:*:*:*:*:*:*:* | before 3.16.60 | Vulnerable | ProtonMail |
- cpe:2.3:a:protonmail:protonmail:*:*:*:*:*:*:*:* Versions before 3.16.60 Vulnerable ·ProtonMail
Remediation
- Fix · CNA WebClient (ProtonMail) Fixed in 3.16.60
Timeline
- 2026-10-02 Threatist record created from CVE-2021-32816
- 2026-10-03 Alias added: GHSA-h97j-5ccr-wj2x
References
Sources
- CVE-2021-32816 · CVE Program
- CVE-2021-32816 · NVD
- FIRST EPSS
- GHSA-h97j-5ccr-wj2x · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences