How severe is CVE-2021-43958?

CVE-2021-43958 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43958 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43958?

CVE-2021-43958 primarily affects Atlassian Crucible. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43958?

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-2021-43958 published?

CVE-2021-43958 was published on 2022-03-16 and last updated on 2026-06-17.

CVE-2021-43958

CVE-2021-43958 is a critical-severity vulnerability in Atlassian Crucible with a CVSS 3.x base score of 9.8. 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-307.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-307
Affected product: Atlassian Crucible
Published: 2022-03-16
Last modified: 2026-06-17

Description

Various rest resources in Fisheye and Crucible before version 4.8.9 allowed remote attackers to brute force user login credentials as rest resources did not check if users were beyond their max failed login limits and therefore required solving a CAPTCHA in addition to providing user credentials for authentication via a improper restriction of excess authentication attempts vulnerability.

Frequently asked questions

What is CVE-2021-43958?: Various rest resources in Fisheye and Crucible before version 4.8.9 allowed remote attackers to brute force user login credentials as rest resources did not check if users were beyond their max failed login limits and therefore required solving a CAPTCHA in addition to providing user credentials for authentication via a improper restriction of excess authentication attempts vulnerability.
How severe is CVE-2021-43958?: CVE-2021-43958 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43958 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43958?: CVE-2021-43958 primarily affects Atlassian Crucible. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43958?: 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-2021-43958 published?: CVE-2021-43958 was published on 2022-03-16 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:atlassian:crucible:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:fisheye:*:*:*:*:*:*:*:*

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