How severe is CVE-2021-47950?

CVE-2021-47950 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-47950 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47950?

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

Does CVE-2021-47950 have an EU (EUVD) identifier?

Yes. CVE-2021-47950 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34810.

When was CVE-2021-47950 published?

CVE-2021-47950 was published on 2026-05-10 and last updated on 2026-06-17.

CVE-2021-47950

CVE-2021-47950 is a medium-severity vulnerability with a CVSS 3.x base score of 6.4. 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 6.4)
CVSS v4: 5.1
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34810
Weakness: CWE-79
Published: 2026-05-10
Last modified: 2026-06-17

Description

Advanced Guestbook 2.4.4 contains a persistent cross-site scripting vulnerability in the smilies administration interface that allows authenticated attackers to inject malicious scripts by manipulating the s_emotion parameter. Attackers can submit POST requests to admin.php with JavaScript code in the s_emotion field, which executes when administrators view the smilies tab.

Frequently asked questions

What is CVE-2021-47950?: Advanced Guestbook 2.4.4 contains a persistent cross-site scripting vulnerability in the smilies administration interface that allows authenticated attackers to inject malicious scripts by manipulating the s_emotion parameter. Attackers can submit POST requests to admin.php with JavaScript code in the s_emotion field, which executes when administrators view the smilies tab.
How severe is CVE-2021-47950?: CVE-2021-47950 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-47950 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47950?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47950 have an EU (EUVD) identifier?: Yes. CVE-2021-47950 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34810.
When was CVE-2021-47950 published?: CVE-2021-47950 was published on 2026-05-10 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

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CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

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