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

CVE-2021-23447 — teddy

MEDIUMFix: rooseveltframework/teddy#518

CVE-2021-23447 is a medium-severity (CVSS 6.1) CWE-843 vulnerability in teddy. 1 public exploit reference exists, so weaponization risk is real. A fix is available for teddy — see the affected versions and patch details below.

Cross-site Scripting in teddy

Also known asGHSA-5f38-9jw2-6r6hSNYK-JS-TEDDY-1579557
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs65th percentile — riskier than 65% of all scored CVEsHighest risk
0.00%0.54%1.09%1.63%0.3%1.1%Apr 26Aug 26Oct 26

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

How urgent is this, really

CVE-2021-23447 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
📦teddy

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

Teddy is a readable and easy to learn templating language. This affects the package teddy before 0.5.9. A type confusion vulnerability can be used to bypass input sanitization when the model content is an array (instead of a string).

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmteddyall versions0.5.9npm install teddy@0.5.9

Affected Products

1 product · 1 configurations
Application
teddyteddy_project
< 0.5.9
range
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 the package teddy before 0.5.9. A type confusion vulnerabil…

snyk.ioNVDOct 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 teddy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update teddy to 0.5.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23447 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Teddy is a readable and easy to learn templating language. This affects the package teddy before 0.5.9. A type confusion vulnerability can be used to bypass input sanitization when the model content is an array (instead of a string).
O3 Security · Impact-Aware SCA

Is CVE-2021-23447 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works