Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
MEDIUM severity

CVE-2021-23416 — curly-bracket-parser

MEDIUM

CVE-2021-23416 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in curly-bracket-parser. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Cross-site Scripting in curly-bracket-parser

Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
1 known
Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk
0.00%0.43%0.86%1.29%0.2%0.8%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-23416 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
📦curly-bracket-parser

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

This affects all versions of package curly-bracket-parser. When used as a template library, it does not properly sanitize the user input.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
📦npmcurly-bracket-parserall versionsNo fix

Affected Products

1 product · 1 configurations
Application
curly-bracket-parsercurly-bracket-parser_project
all
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

This affects all versions of package curly-bracket-parser. When used as …

snyk.ioNVDAug 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for curly-bracket-parser, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    No patched version of curly-bracket-parser has shipped for CVE-2021-23416 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

This affects all versions of package curly-bracket-parser. When used as a template library, it does not properly sanitize the user input.
O3 Security · Impact-Aware SCA

Is CVE-2021-23416 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works