How severe is CVE-2021-4296?

CVE-2021-4296 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-4296 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4296?

CVE-2021-4296 affects W3 Unicorn. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4296?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-4296 published?

CVE-2021-4296 was published on 2022-12-29 and last updated on 2026-06-17.

CVE-2021-4296

CVE-2021-4296 is a low-severity vulnerability in W3 Unicorn with a CVSS 3.x base score of 3.5. 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-79.

Key facts

Severity: Low (CVSS 3.x base score 3.5)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: W3 Unicorn
Published: 2022-12-29
Last modified: 2026-06-17

Description

A vulnerability, which was classified as problematic, has been found in w3c Unicorn. This issue affects the function ValidatorNuMessage of the file src/org/w3c/unicorn/response/impl/ValidatorNuMessage.java. The manipulation of the argument message leads to cross site scripting. The attack may be initiated remotely. The name of the patch is 51f75c31f7fc33859a9a571311c67ae4e95d9c68. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-217019.

Frequently asked questions

What is CVE-2021-4296?: A vulnerability, which was classified as problematic, has been found in w3c Unicorn. This issue affects the function ValidatorNuMessage of the file src/org/w3c/unicorn/response/impl/ValidatorNuMessage.java. The manipulation of the argument message leads to cross site scripting. The attack may be initiated remotely. The name of the patch is 51f75c31f7fc33859a9a571311c67ae4e95d9c68. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-217019.
How severe is CVE-2021-4296?: CVE-2021-4296 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-4296 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4296?: CVE-2021-4296 affects W3 Unicorn. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-4296?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4296 published?: CVE-2021-4296 was published on 2022-12-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:w3:unicorn:*:*:*:*:*:*:*:*

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