CVE-2026-21577CWE-400denial-of-service

CVE-2026-21577

Medium · published July 21, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
35.8
In the wild
Unconfirmed
What it is

This High severity DoS (Denial of Service) vulnerability was introduced in versions 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 (Denial of Service) vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to cause a resource to be unavailable for its intended users by temporarily or indefinitely disrupting services of a host connected to a network.

Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.17

Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.7

See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center from the download center ([https://www.atlassian.com/software/confluence/download-archives]).

This vulnerability was reported via our Penetration Testing program.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00426 · 35.8th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2026-07-21T22:16Z
Affected products (9)
ProductVersionsFixed in
atlassian/confluence_data_center≥ 9.0.1, ≤ 9.0.3—
atlassian/confluence_data_center≥ 9.1.0, ≤ 9.1.1—
atlassian/confluence_data_center≥ 9.2.0, ≤ 9.2.15—
atlassian/confluence_data_center≥ 9.3.1, ≤ 9.3.2—
atlassian/confluence_data_center≥ 9.4.0, ≤ 9.4.1—
atlassian/confluence_data_center≥ 9.5.1, ≤ 9.5.4—
atlassian/confluence_data_center≥ 10.0.2, ≤ 10.0.3—
atlassian/confluence_data_center≥ 10.1.0, ≤ 10.1.2—
atlassian/confluence_data_center≥ 10.2.0, ≤ 10.2.6—
References (2)
EPSS history
Timeline
  • 21 JUL 17:00Z
    This High severity DoS (Denial of Service) vulnerability was introduced in versions 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…
    cvelistv5