7.1

CVE-2026-21577: atlassian confluence_data_center Uncontrolled Resource Consumption

Analyzed
Published 21-07-2026Last modified 22-07-2026

Vulnerability summary

CVE-2026-21577 is a high (CVSS 7.1) Uncontrolled Resource Consumption vulnerability in atlassian confluence_data_center. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v4.0 (CVE.org)
EPSS score
0.43%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 21-07-2026
    PublishedVulnerability first disclosed.
  2. 22-07-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.43% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Atlassian1 product
  • confluence_data_center10.2.0 to 10.2.6 | 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 9.2.15 | 9.1.0 to 9.1.1 | 9.0.1 to 9.0.3 | ≥ 9.0.1, ≤ 9.0.3 | ≥ 9.1.0, ≤ 9.1.1 | ≥ 9.2.0, ≤ 9.2.15 | ≥ 9.3.1, ≤ 9.3.2 | ≥ 9.4.0, ≤ 9.4.1 | ≥ 9.5.1, ≤ 9.5.4 | ≥ 10.0.2, ≤ 10.0.3 | ≥ 10.1.0, ≤ 10.1.2 | ≥ 10.2.0, ≤ 10.2.6

1 vendor · 1 product

References

2 links