How severe is CVE-2021-39222?

CVE-2021-39222 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-39222 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39222?

CVE-2021-39222 affects Nextcloud Talk. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39222?

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

When was CVE-2021-39222 published?

CVE-2021-39222 was published on 2021-11-15 and last updated on 2026-06-17.

CVE-2021-39222

CVE-2021-39222 is a medium-severity vulnerability in Nextcloud Talk 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 v2: 4.3
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Nextcloud Talk
Published: 2021-11-15
Last modified: 2026-06-17

Description

Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Talk application was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Talk application is upgraded to patched versions 10.0.7, 10.1.4, 11.1.2, 11.2.0 or 12.0.0. As a workaround, use a browser that has support for Content-Security-Policy.

Frequently asked questions

What is CVE-2021-39222?: Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Talk application was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Talk application is upgraded to patched versions 10.0.7, 10.1.4, 11.1.2, 11.2.0 or 12.0.0. As a workaround, use a browser that has support for Content-Security-Policy.
How severe is CVE-2021-39222?: CVE-2021-39222 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-39222 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39222?: CVE-2021-39222 affects Nextcloud Talk. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39222?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39222 published?: CVE-2021-39222 was published on 2021-11-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:talk:*:*:*:*:*:*:*:*

More vulnerabilities in Nextcloud Talk

CVE-2020-8180 — Critical (CVSS 9.9): A too lax check in Nextcloud Talk 6.0.4, 7.0.2 and 8.0.7 allowed a code injection when a not correctly sanitized talk…
CVE-2021-32689 — High (CVSS 8.1): Nextcloud Talk is a fully on-premises audio/video and chat communication service. In versions prior to 11.2.2, if a…
CVE-2023-39957 — High (CVSS 7.8): Nextcloud Talk Android allows users to place video and audio calls through Nextcloud on Android. Prior to version…
CVE-2021-32676 — Medium (CVSS 6.5): Nextcloud Talk is a fully on-premises audio/video and chat communication service. Password protected shared chats in…
CVE-2018-3781 — Medium (CVSS 5.4): A missing sanitization of search results for an autocomplete field in NextCloud Talk <3.2.5 could lead to a stored XSS…
CVE-2019-15619 — Medium (CVSS 4.8): Improper neutralization of file names, conversation names and board names in Nextcloud Server 16.0.3, Nextcloud Talk…

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