Medium severity5.3NVD Advisory· Published Dec 17, 2021· Updated Jun 17, 2026
CVE-2021-43838
CVE-2021-43838
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 `` 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.
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Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
jsx-slacknpm | < 4.5.1 | 4.5.1 |
Affected products
3Patches
Vulnerability mechanics
References
4- github.com/yhatt/jsx-slack/commit/36e4a10405e4c7745333e245fcc5029c02c7065dnvdPatchThird Party AdvisoryWEB
- github.com/yhatt/jsx-slack/security/advisories/GHSA-55xv-f85c-248qnvdExploitPatchThird Party AdvisoryWEB
- github.com/advisories/GHSA-55xv-f85c-248qghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2021-43838ghsaADVISORY
News mentions
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