How severe is CVE-2021-29451?

CVE-2021-29451 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-29451?

CVE-2021-29451 affects the following packages: com.manydesigns:portofino-dispatcher (Maven), com.manydesigns:portofino-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-29451?

Update com.manydesigns:portofino-dispatcher to 5.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29451 is resolved across your whole dependency graph.

How do I detect CVE-2021-29451 in my Maven dependencies?

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

How do I mitigate CVE-2021-29451 if there is no patch (or I can't update yet)?

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.

Is CVE-2021-29451 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-29451 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-2021-29451?

CVE-2021-29451 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 60th 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-2021-29451?

CVE-2021-29451 is classified as CWE-347 (CWE-347). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-29451 published, and has it been updated?

CVE-2021-29451 was published on April 16, 2021 and was last updated on July 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

CRITICAL severity

CVE-2021-29451 — portofino-dispatcher

CRITICALFix: ManyDesigns/Portofino@8c754a0

CVE-2021-29451 is a critical-severity (CVSS 9.1) CWE-347 vulnerability in com.manydesigns:portofino-dispatcher. A fix is available for com.manydesigns:portofino-dispatcher — see the affected versions and patch details below.

Missing validation of JWT signature in `ManyDesigns/Portofino`

Also known asGHSA-6g3c-2mh5-7q6x

Published

Apr 16, 2021

Updated

Jul 9, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs60th percentile — riskier than 60% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-29451 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

2 pkgs affected

☕com.manydesigns:portofino-dispatcher☕com.manydesigns:portofino-core

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

Description

Impact

Portofino is an open source web development framework. Portofino before version 5.2.1 did not properly verify the signature of JSON Web Tokens. This allows forging a valid JWT.

Patches

The issue will be patched in the upcoming 5.2.1 release.

For more information

If you have any questions or comments about this advisory:

Open an issue in https://github.com/ManyDesigns/Portofino

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.manydesigns:portofino-dispatcher`	≥ 5.0.0&&< 5.2.1	5.2.1`com.manydesigns:portofino-dispatcher:5.2.1`
☕Maven	`com.manydesigns:portofino-core`	≥ 5.0.0&&< 5.2.1	5.2.1`com.manydesigns:portofino-core:5.2.1`

Affected Products

1 product · 1 configurations

Application

portofinomanydesigns

≥ 5.0.0 && < 5.2.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.manydesigns:portofino-dispatcher, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.manydesigns:portofino-dispatcher to 5.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29451 is resolved across your whole dependency graph.
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

### Impact [Portofino](https://github.com/ManyDesigns/Portofino) is an open source web development framework. Portofino before version 5.2.1 did not properly verify the signature of JSON Web Tokens. This allows forging a valid JWT. ### Patches The issue will be patched in the upcoming 5.2.1 release. ### For more information If you have any questions or comments about this advisory: * Open an issue in [https://github.com/ManyDesigns/Portofino](https://github.com/ManyDesigns/Portofino)

O3 Security · Impact-Aware SCA

Is CVE-2021-29451 in your dependencies?

Find it across Maven, including transitive dependencies.

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CVSS Score

9.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Raw vector

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

CWE Classification

CWE-347CWE-347

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

Portofino

3.8/10

Code-Review4/10

Maintained0/10

Branch-Protection0/10

Assessed Oct 12, 2026

Timeline

Disclosed

Apr 16, 2021

Last updated

Jul 9, 2026

Identifiers

CVE-2021-29451

GHSA-6g3c-2mh5-7q6x

References

Advisorygithub.com Advisorymvnrepository.com Advisorynvd.nist.gov Fixgithub.com

Related vulnerabilities

This CVE is critical severity; 1 of 8 other CVEs with CWE-347 is rated as high or higher (top: critical).

CVE-2026-59163CVE-2026-86038CVE-2026-86080GHSA-73p9-6hrp-8qhrCVE-2026-54736CVE-2026-54155GHSA-fhgh-wq4q-r37xCVE-2026-53501Browse all CWE-347

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 9, 2026

CVE-2021-29451 — portofino-dispatcher

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Impact

Patches

For more information

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-29451 in your dependencies?