How severe is CVE-2021-26086?

CVE-2021-26086 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-26086 being actively exploited?

Yes. CVE-2021-26086 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-11-12, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-26086?

CVE-2021-26086 primarily affects Atlassian Jira Data Center. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26086?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-26086 have an EU (EUVD) identifier?

Yes. CVE-2021-26086 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12907. It is also flagged as exploited in the EUVD (since 2024-11-12).

When was CVE-2021-26086 published?

CVE-2021-26086 was published on 2021-08-16 and last updated on 2026-06-17.

CVE-2021-26086

CVE-2021-26086 is a medium-severity vulnerability in Atlassian Jira Data Center with a CVSS 3.x base score of 5.3. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-11-12). The underlying weakness is classified as CWE-22.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 100% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2024-11-12)
EU (EUVD) id: EUVD-2021-12907
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2024-11-12)
Weakness: CWE-22
Affected product: Atlassian Jira Data Center
Published: 2021-08-16
Last modified: 2026-06-17

Description

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerability in the /WEB-INF/web.xml endpoint. The affected versions are before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1.

Frequently asked questions

What is CVE-2021-26086?: Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerability in the /WEB-INF/web.xml endpoint. The affected versions are before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1.
How severe is CVE-2021-26086?: CVE-2021-26086 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-26086 being actively exploited?: Yes. CVE-2021-26086 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-11-12, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-26086?: CVE-2021-26086 primarily affects Atlassian Jira Data Center. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26086?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-26086 have an EU (EUVD) identifier?: Yes. CVE-2021-26086 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12907. It is also flagged as exploited in the EUVD (since 2024-11-12).
When was CVE-2021-26086 published?: CVE-2021-26086 was published on 2021-08-16 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:atlassian:jira_data_center:*:*:*:*:*:*:*:*
cpe:2.3:a:atlassian:jira_server:*:*:*:*:*:*:*:*

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