How severe is CVE-2021-32645?

CVE-2021-32645 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-32645?

CVE-2021-32645 affects the following packages: hyn/multi-tenant (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-32645?

Update hyn/multi-tenant to 5.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32645 is resolved across your whole dependency graph.

How do I detect CVE-2021-32645 in my Packagist dependencies?

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

How do I mitigate CVE-2021-32645 if there is no patch (or I can't update yet)?

Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Is CVE-2021-32645 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-32645 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-32645?

CVE-2021-32645 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 63th 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-2021-32645?

CVE-2021-32645 is classified as Open Redirect (CWE-601). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-32645 published, and has it been updated?

CVE-2021-32645 was published on May 27, 2021 and was last updated on October 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

MEDIUM severity

CVE-2021-32645 — multi-tenant

MEDIUMFix: tenancy/multi-tenant@9c837a2

CVE-2021-32645 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in hyn/multi-tenant. A fix is available for hyn/multi-tenant — see the affected versions and patch details below.

Open Redirect

Also known asGHSA-4r8q-gv9j-3xx6

Published

May 27, 2021

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs63th percentile — riskier than 63% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘hyn/multi-tenant

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

Impact

In some situations, it is possible to have open redirects where users can be redirected from your site to any other site using a specially crafted URL. This is only the case for installations where the default Hostname Identification is used and the environment uses tenants that have force_https set to true (default: false)

Patches

Version 5.7.2 contains the relevant patches to fix this bug. Stripping the URL from special characters to prevent specially crafted URL's from being redirected to.

Workarounds

There is a simple way to work around the security issue

Set the force_https to every tenant to false

References

https://nvd.nist.gov/vuln/detail/CVE-2018-11784

For more information

If you have any questions or comments about this advisory:

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`hyn/multi-tenant`	≥ 5.6.0&&< 5.7.2	5.7.2`composer require hyn/multi-tenant:^5.7.2`

Affected Products

1 product · 1 configurations

Application

multi-tenanttenancy

≥ 5.6.0 && < 5.7.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hyn/multi-tenant, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hyn/multi-tenant to 5.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32645 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Frequently Asked Questions

### Impact In some situations, it is possible to have open redirects where users can be redirected from your site to any other site using a specially crafted URL. This is only the case for installations where the default Hostname Identification is used and the environment uses tenants that have `force_https` set to `true` (default: `false`) ### Patches Version 5.7.2 contains the relevant patches to fix this bug. Stripping the URL from special characters to prevent specially crafted URL's from being redirected to. ### Workarounds There is a simple way to work around the security issue - Set t