CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2021-43838
High (7.5) in jsx-slack project jsx-slack. EPSS 1.4% chance of exploitation in the next 30 days. Fixed in jsx-slack 4.5.1.
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.
Severity
- EPSS
- 1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-1333, CWE-400
- Published
- Modified
- Record from
- the NVD, synced
Affected
- jsx-slack_project:jsx-slack
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-55xv-f85c-248q | npm | jsx-slack | <4.5.1 | 4.5.1 |
References
- https://github.com/yhatt/jsx-slack/commit/36e4a10405e4c7745333e245fcc5029c02c7065d
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248q
- https://github.com/yhatt/jsx-slack/commit/36e4a10405e4c7745333e245fcc5029c02c7065d
- https://github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248q