How severe is CVE-2021-43676?

CVE-2021-43676 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-43676?

CVE-2021-43676 affects the following packages: matyhtf/framework (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-43676?

Update matyhtf/framework to 3.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43676 is resolved across your whole dependency graph.

How do I detect CVE-2021-43676 in my Packagist dependencies?

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

How do I mitigate CVE-2021-43676 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-43676 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-43676, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-43676?

CVE-2021-43676 has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 72th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-43676?

CVE-2021-43676 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-43676 published, and has it been updated?

CVE-2021-43676 was published on December 4, 2021 and was last updated on July 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

CRITICAL severity

CVE-2021-43676 — framework

CRITICALFix: matyhtf/framework@2508460

CVE-2021-43676 is a critical-severity (CVSS 9.8) Path Traversal vulnerability in matyhtf/framework. 1 public exploit reference exists, so weaponization risk is real. A fix is available for matyhtf/framework — see the affected versions and patch details below.

Path manipulation in matyhtf/framework

Published

Dec 4, 2021

Updated

Jul 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Oct 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs72th percentile — riskier than 72% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-43676 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 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

🐘matyhtf/framework

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

Description

matyhtf framework v3.0.5 is affected by a path manipulation vulnerability in Smarty.class.php. The issue was fixed in version 3.0.6.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`matyhtf/framework`	all versions	3.0.6`composer require matyhtf/framework:^3.0.6`

Affected Products

1 product · 1 configurations

Application

swoole php frameworkswoole

1 version

3.0.5

Exploits & PoCs

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

matyhtf framework v3.0.5 is affected by a path manipulation vulnerabilit…

github.comNVDDec 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matyhtf/framework, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update matyhtf/framework to 3.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43676 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

matyhtf framework v3.0.5 is affected by a path manipulation vulnerability in Smarty.class.php. The issue was fixed in version 3.0.6.

O3 Security · Impact-Aware SCA

Is CVE-2021-43676 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

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

CWE Classification

CWE-22Path Traversal

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

framework

3.0/10

Maintained0/10

Code-Review0/10

Vulnerabilities10/10

Branch-Protection0/10

Assessed May 19, 2025

Timeline

Disclosed

Dec 4, 2021

First exploit

Dec 6, 2021

3 days after disclosure — rapid exploitation

Last updated

Jul 20, 2026

Identifiers

CVE-2021-43676

References

Advisorynvd.nist.gov Advisorygithub.com Webgithub.com Webgithub.com Webgithub.com Packagegithub.com

Related vulnerabilities

This CVE is critical severity; 1 of 8 other CVEs with CWE-22 is rated as high or higher (top: critical).

CVE-2026-63445CVE-2026-72697CVE-2026-74907CVE-2026-63225CVE-2026-86071CVE-2026-45140CVE-2026-72695CVE-2026-85731Browse all CWE-22

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 20, 2026

CVE-2021-43676 — framework

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-43676 in your dependencies?