CVE Vulnerabilities

CVE-2021-23364

Inefficient Regular Expression Complexity

Published: Apr 28, 2021 | Modified: Jun 17, 2026
CVSS 3.x
5.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
5.3 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Ubuntu
MEDIUM
root.io logo minimus.io logo echo.ai logo

The package browserslist from 4.0.0 and before 4.16.5 are vulnerable to Regular Expression Denial of Service (ReDoS) during parsing of queries.

Weakness

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

Affected Software

NameVendorStart VersionEnd Version
BrowserslistBrowserslist_project4.0.0 (including)4.16.5 (excluding)
Red Hat Quay 3RedHatquay/quay-rhel8:v3.6.0-62*
Node-browserslistUbuntubionic*
Node-browserslistUbuntufocal*
Node-browserslistUbuntugroovy*
Node-browserslistUbuntuhirsute*
Node-browserslistUbuntuimpish*
Node-browserslistUbuntukinetic*
Node-browserslistUbuntuupstream*

Potential Mitigations

References