How severe is CVE-2021-28968?

CVE-2021-28968 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-28968 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-2021-28968?

CVE-2021-28968 affects Gnu Punbb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28968?

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

When was CVE-2021-28968 published?

CVE-2021-28968 was published on 2021-03-22 and last updated on 2026-06-17.

CVE-2021-28968

CVE-2021-28968 is a medium-severity vulnerability in Gnu Punbb with a CVSS 3.x base score of 5.4. 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: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Gnu Punbb
Published: 2021-03-22
Last modified: 2026-06-17

Description

An issue was discovered in PunBB before 1.4.6. An XSS vulnerability in the [email] BBcode tag allows (with authentication) injecting arbitrary JavaScript into any forum message.

Frequently asked questions

What is CVE-2021-28968?: An issue was discovered in PunBB before 1.4.6. An XSS vulnerability in the [email] BBcode tag allows (with authentication) injecting arbitrary JavaScript into any forum message.
How severe is CVE-2021-28968?: CVE-2021-28968 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-28968 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-2021-28968?: CVE-2021-28968 affects Gnu Punbb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28968?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28968 published?: CVE-2021-28968 was published on 2021-03-22 and last updated on 2026-06-17.

References

https://punbb.informer.com/

Affected products (1)

cpe:2.3:a:gnu:punbb:*:*:*:*:*:*:*:*

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