NVD / CVE Program· CNA atlassian

CVE-2026-21577: 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

Noroxi assessment

Priority: Monitor (action score 28/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.42% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.1 · v4.0—No exploit No fix recorded

Denial of service

Published: Jul 21, 2026
Updated: Oct 24, 2026
EPSS: 0.4% · 37th percentile
CWE: CWE-400

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · atlassian: 7.1; NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
atlassian	confluence data center	cpe:2.3:a:atlassian:confluence_data_center

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

atlassian confluence data center9.0.1 and later · up to 9.0.3 inclusive
atlassian confluence data center9.1.0 and later · up to 9.1.1 inclusive
atlassian confluence data center9.2.0 and later · up to 9.2.15 inclusive
atlassian confluence data center9.3.1 and later · up to 9.3.2 inclusive
atlassian confluence data center9.4.0 and later · up to 9.4.1 inclusive
atlassian confluence data center9.5.1 and later · up to 9.5.4 inclusive
atlassian confluence data center10.0.2 and later · up to 10.0.3 inclusive
atlassian confluence data center10.1.0 and later · up to 10.1.2 inclusive
atlassian confluence data center10.2.0 and later · up to 10.2.6 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (atlassian). Independent of NVD's CPE analysis and usually ahead of it.

Atlassian Confluence Data Center
- 10.2.7 to 10.2.14, 9.2.17 to 9.2.22not affected
- 10.2.0 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 9.0.3affected

Same product

atlassian: all records

Other highest-scoring records for the same primary product.

CVE-2023-22527A template injection vulnerability on older versions of Confluence Data Center and Server allows an unauthenticated attacker to achieve RCE KEV
99Now
CVE-2023-22518All versions of Confluence Data Center and Server are affected by this unexploited vulnerability.KEV
99Now
CVE-2023-22515Atlassian has been made aware of an issue reported by a handful of customers where external attackers may have exploited a previously unknowKEV
99Now

Published before and after this one in the same product

← EarlierCVE-2024-21703Nov 27, 2024 · This Medium severity Security Misconfiguration vulnerability was introduced in version 8.8.1 of Confluence Data Center and Server for Window
25Monitor
← EarlierCVE-2025-22166Oct 21, 2025 · This High severity DoS (Denial of Service) vulnerability was introduced in version 2.0 of Confluence Data Center.
33Monitor
Later →CVE-2026-21579Jul 21, 2026 · This High severity Information Disclosure vulnerability was introduced in versions 7.17.0, 7.19.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 10.0.2
32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-2158856 days apartThis 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,
28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

AtlassianBugcrowd · paid · up to $12,000

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: X

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

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-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

confluence.atlassian.com/pages/viewpage.action?pageId=1821999345

Show all references (1 more)

jira.atlassian.com/browse/CONFSERVER-104334

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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