CVE-2021-43838

high

Description

jsx-slack is a library for building JSON objects for Slack Block Kit surfaces from JSX. In versions prior to 4.5.1 users are vulnerable to a regular expression denial-of-service (ReDoS) attack. If attacker can put a lot of JSX elements into `<blockquote>` tag, an internal regular expression for escaping characters may consume an excessive amount of computing resources. jsx-slack v4.5.1 has patched to a regex for escaping blockquote characters. Users are advised to upgrade as soon as possible.

References

https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248q

https://github.com/yhatt/jsx-slack/commit/36e4a10405e4c7745333e245fcc5029c02c7065d

Details

Source: Mitre, NVD

Published: 2021-12-17

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 7.5

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

Severity: High

EPSS

EPSS: 0.00317