How severe is CVE-2021-47955?

CVE-2021-47955 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-2021-47955 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47955?

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

Does CVE-2021-47955 have an EU (EUVD) identifier?

Yes. CVE-2021-47955 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34823.

When was CVE-2021-47955 published?

CVE-2021-47955 was published on 2026-05-16 and last updated on 2026-06-17.

CVE-2021-47955

CVE-2021-47955 is a medium-severity vulnerability 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 v4: 5.1
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34823
Weakness: CWE-79
Published: 2026-05-16
Last modified: 2026-06-17

Description

CouchCMS 2.2.1 contains a cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript by uploading malicious SVG files through the file upload functionality. Attackers can upload SVG files containing embedded script tags to the browse.php endpoint, which are then executed in users' browsers when the files are accessed or previewed.

Frequently asked questions

What is CVE-2021-47955?: CouchCMS 2.2.1 contains a cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript by uploading malicious SVG files through the file upload functionality. Attackers can upload SVG files containing embedded script tags to the browse.php endpoint, which are then executed in users' browsers when the files are accessed or previewed.
How severe is CVE-2021-47955?: CVE-2021-47955 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-2021-47955 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47955?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47955 have an EU (EUVD) identifier?: Yes. CVE-2021-47955 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34823.
When was CVE-2021-47955 published?: CVE-2021-47955 was published on 2026-05-16 and last updated on 2026-06-17.

References

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

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
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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