How severe is CVE-2021-29451?

CVE-2021-29451 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-29451 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29451?

CVE-2021-29451 affects Manydesigns Portofino. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29451?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-29451 published?

CVE-2021-29451 was published on 2021-04-16 and last updated on 2026-06-17.

CVE-2021-29451

CVE-2021-29451 is a critical-severity vulnerability in Manydesigns Portofino with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Manydesigns Portofino
Published: 2021-04-16
Last modified: 2026-06-17

Description

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. The issue will be patched in the upcoming 5.2.1 release.

Frequently asked questions

What is CVE-2021-29451?: 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. The issue will be patched in the upcoming 5.2.1 release.
How severe is CVE-2021-29451?: CVE-2021-29451 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-29451 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29451?: CVE-2021-29451 affects Manydesigns Portofino. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29451?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-29451 published?: CVE-2021-29451 was published on 2021-04-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:manydesigns:portofino:*:*:*:*:*:*:*:*

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