How severe is CVE-2021-43956?

CVE-2021-43956 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-43956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43956?

CVE-2021-43956 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-2021-43956?

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

When was CVE-2021-43956 published?

CVE-2021-43956 was published on 2022-03-16 and last updated on 2026-06-17.

CVE-2021-43956

CVE-2021-43956 is a medium-severity vulnerability in Atlassian Crucible with a CVSS 3.x base score of 6.1. 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-1321.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1321
Affected product: Atlassian Crucible
Published: 2022-03-16
Last modified: 2026-06-17

Description

The jQuery deserialize library in Fisheye and Crucible before version 4.8.9 allowed remote attackers to to inject arbitrary HTML and/or JavaScript via a prototype pollution vulnerability.

Frequently asked questions

What is CVE-2021-43956?: The jQuery deserialize library in Fisheye and Crucible before version 4.8.9 allowed remote attackers to to inject arbitrary HTML and/or JavaScript via a prototype pollution vulnerability.
How severe is CVE-2021-43956?: CVE-2021-43956 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-43956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43956?: CVE-2021-43956 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-2021-43956?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43956 published?: CVE-2021-43956 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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