CVE & CISA-KEV Catalog

CVE-2026-21589

HIGHCISA KEVEPSS 100th pctl
7.5
CVSS v3
NVD

Description

This is a vulnerability in Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center. Crowd Data Center, Crucible and Fisheye. This Arbitrary File Access vulnerability allows an unauthenticated attacker to access specific files within the web application root directory in affected versions. Exploitation requires prior knowledge of the target file's exact name and path; this vulnerability does not allow attackers to enumerate or list directory contents. In some configurations, there may be some sensitive files that make this highly severe. This vulnerability allows an unauthenticated remote attacker to access specific files within the web application root directory in affected versions. The vulnerability must be addressed for affected versions of: -- Bitbucket Data Center, introduced in version >= 4.6.0, fix versions: 9.4.26, 10.2.8, 10.5.1 -- Confluence Data Center, introduced in version >= 5.10.0, fix versions 9.2.26, 10.2.19 -- Crowd Data Center, introduced in version >= 2.11.0, fix versions 6.3.7, 7.0.3, 7.1.7, 7.2.4 -- Jira Software Data Center, introduced in version >= 7.1.0, fix versions 9.12.40, 10.3.26, 11.3.12 -- Jira Service Management Data Center, introduced in version >= 3.1.0, fix versions 5.12.40, 10.3.26, 11.3.12 -- Bamboo Data Center >= 7.0.1, fix versions 10.2.24, 12.1.12 -- Crucible, fix versions 4.9.15 -- Fisheye, fix version 4.9.15 -- Exploitation requires prior knowledge of the target file's exact name and path. The vulnerability does not include the capability to enumerate or list directory contents.

How to fix

Remediation Available
Jira Service Management Long Term SupportWindows application
Affected:5.13.0 10.3.26Fixed in:10.3.26
Affected:3.1.0 5.12.40Fixed in:5.12.40
Affected:10.4.0 11.3.12Fixed in:11.3.12
Affected:4.14.0 5.12.40Fixed in:5.12.40

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Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityNone
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploit Intelligence

99.48%probability of exploitation in 30 days
100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Remediation due: 2026-10-18

References

Related Vulnerabilities

Other CWE-552 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2020-17519High7.598%KEVFix
CVE-2025-11371High7.592%KEVFix
CVE-2023-50164Critical9.881%-Fix
CVE-2016-3715Medium5.575%KEVFix
CVE-2020-15175High7.470%-Fix
CVE-2021-39316High7.566%--

Common questions

How do I fix CVE-2026-21589?

Upgrade Jira Service Management Long Term Support to 10.3.26 or later.

Is CVE-2026-21589 being actively exploited?

Yes. CVE-2026-21589 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2026-10-18. Treat it as a priority whatever its CVSS score says.

How severe is CVE-2026-21589?

CVE-2026-21589 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-21589 affect?

Published advisories record a fix for Jira Service Management Long Term Support (Windows application). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This vulnerability is actively exploited in the wild

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-29.