How severe is CVE-2023-22521?

CVE-2023-22521 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-22521 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-22521?

CVE-2023-22521 primarily affects Atlassian Crowd. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-22521?

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

When was CVE-2023-22521 published?

CVE-2023-22521 was published on 2023-11-21 and last updated on 2026-06-17.

CVE-2023-22521

CVE-2023-22521 is a high-severity vulnerability in Atlassian Crowd with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Atlassian Crowd
Published: 2023-11-21
Last modified: 2026-06-17

Description

This High severity RCE (Remote Code Execution) vulnerability was introduced in version 3.4.6 of Crowd Data Center and Server. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 8.0, allows an authenticated attacker to execute arbitrary code which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction. Atlassian recommends that Crowd Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Crowd Data Center and Server 3.4: Upgrade to a release greater than or equal to 5.1.6 Crowd Data Center and Server 5.2: Upgrade to a release greater than or equal to 5.2.1 See the release notes ([https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html]). You can download the latest version of Crowd Data Center and Server from the download center ([https://www.atlassian.com/software/crowd/download-archive]). This vulnerability was discovered by m1sn0w and reported via our Bug Bounty program

Frequently asked questions

What is CVE-2023-22521?: This High severity RCE (Remote Code Execution) vulnerability was introduced in version 3.4.6 of Crowd Data Center and Server. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 8.0, allows an authenticated attacker to execute arbitrary code which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction. Atlassian recommends that Crowd Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Crowd Data Center and Server 3.4: Upgrade to a release greater than or equal to 5.1.6 Crowd Data Center and Server 5.2: Upgrade to a release greater than or equal to 5.2.1 See the release notes ([https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html]). You can download the latest version of Crowd Data Center and Server from the download center ([https://www.atlassian.com/software/crowd/download-archive]). This vulnerability was discovered by m1sn0w and reported via our Bug Bounty program
How severe is CVE-2023-22521?: CVE-2023-22521 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-22521 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-22521?: CVE-2023-22521 primarily affects Atlassian Crowd. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-22521?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-22521 published?: CVE-2023-22521 was published on 2023-11-21 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:atlassian:crowd:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:crowd:5.2.0:*:*:*:*:*:*:*

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