Bamboo Data Center: Improper Authorization
CVE-2026-21584 is a high-severity improper authorization vulnerability in Bamboo Data Center from Atlassian, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Bamboo Data Center versions: 12.1.0 to 12.1.9; 12.0.0 to 12.0.2; 11.0.0 to 11.0.8, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Bamboo to 10.2.22 or 12.1.10, whichever matches your release line, or a later version.
- Read the advisory on confluence.atlassian.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Atlassian | Bamboo Data Center | 12.1.0 to 12.1.9; 12.0.0 to 12.0.2; 11.0.0 to 11.0.8; 10.2.0 to 10.2.21; 10.1.0 to 10.1.1; 10.0.0 to 10.0.3 | Not stated |
| Atlassian | Bamboo | 10.0.0 up to, but not including, 10.2.22; 11.0.0 up to, but not including, 12.1.10 | 10.2.22, 12.1.10 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.6 | High | CNA (atlassian.com) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
This High severity Improper Authorization vulnerability was introduced in versions 10.0.0, 10.1.0, 10.2.0, 11.0.0, 12.0.0, and 12.1.0 of Bamboo Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.6, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources or functionality, possibly providing attackers with sensitive information or even execute arbitrary code. Atlassian recommends that Bamboo 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: * Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.22 * Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.10 See the release notes (https://confluence.atlassian.com/bambooreleases/bamboo-release-notes-1189793869.html). You can download the latest version of Bamboo Data Center from the download center (https://www.atlassian.com/software/bamboo/download-archives). This vulnerability was reported via our Penetration Testing program.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authorization
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Bamboo Data Center
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 8.0 High severity
- 8.1 High severity
- 8.8 High severity
Recent Improper Authorization vulnerabilities
- 9.9 Critical severity
- 8.3 High severity
- 8.8 High severity
- 9.1 Critical severity
- 7.1 High severity
- 9.6 Critical severity
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