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01 Record

CVE-2026-21588

This High severity DoS (Denial of Service) vulnerability was introduced in versions 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This DoS

HighPUBLISHEDCNA: atlassian
CNA base score7.1 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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02 Description

This High severity DoS (Denial of Service) vulnerability was introduced in versions 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This DoS

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.39% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 33.6% of scored records. A rank, not a probability.
NVD base score
7.1 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD analysis status
Awaiting Analysis. NVD last modified this record on 2026-09-16.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-09-15 17:00Z1 MO AGO
Last updated
2026-09-15 23:21Z1 MO AGO
Reserved
2026-01-01
Assigning CNA
atlassian
Record state
PUBLISHED
Severity
High (CVSS 7.1)
CNA CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weaknesses
  • CWE-400Uncontrolled Resource ConsumptionClass
Data version
5.2
Document digest
be1080b587c8d956950305d722c63f7be16f854d696f87b4ef27bc0f6edb4c73

05 Affected products

VendorProductVersionsPlatforms
AtlassianConfluence Data Center10.2.0 to 10.2.15, 10.1.0 to 10.1.2, 10.0.2 to 10.0.3, 9.5.1 to 9.5.4, 9.4.0 to 9.4.1, 9.3.1 to 9.3.2, 9.2.0 to 9.2.23, 9.1.0 to 9.1.1, 8.9.7 to 8.9.8—

06 References