How severe is CVE-2021-29459?

CVE-2021-29459 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2021-29459 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29459?

CVE-2021-29459 affects Xwiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29459?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-29459 published?

CVE-2021-29459 was published on 2021-04-20 and last updated on 2026-06-17.

CVE-2021-29459

CVE-2021-29459 is a critical-severity vulnerability in Xwiki with a CVSS 3.x base score of 9.6. 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: Critical (CVSS 3.x base score 9.6)
CVSS v2: 4.3
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Xwiki
Published: 2021-04-20
Last modified: 2026-06-17

Description

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. It is possible to persistently inject scripts in XWiki versions prior to 12.6.3 and 12.8. Unregistred users can fill simple text fields. Registered users can fill in their personal information and (if they have edit rights) fill the values of static lists using App Within Minutes. There is no easy workaround except upgrading XWiki. The vulnerability has been patched on XWiki 12.8 and 12.6.3.

Frequently asked questions

What is CVE-2021-29459?: XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. It is possible to persistently inject scripts in XWiki versions prior to 12.6.3 and 12.8. Unregistred users can fill simple text fields. Registered users can fill in their personal information and (if they have edit rights) fill the values of static lists using App Within Minutes. There is no easy workaround except upgrading XWiki. The vulnerability has been patched on XWiki 12.8 and 12.6.3.
How severe is CVE-2021-29459?: CVE-2021-29459 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2021-29459 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29459?: CVE-2021-29459 affects Xwiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29459?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-29459 published?: CVE-2021-29459 was published on 2021-04-20 and last updated on 2026-06-17.

References

https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-5c66-v29h-xjh8

Affected products (1)

cpe:2.3:a:xwiki:xwiki:*:*:*:*:*:*:*:*

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