CVE-2026-21587 in Jira Service Management Data Center
Summary
by MITRE • 09/15/2026
This High severity Improper Authorization vulnerability was introduced in version 11.3.0 of Jira Service Management Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.1, 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 Jira Service Management 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: * Jira Service Management Data Center 11.3: Upgrade to a release greater than or equal to 11.3.11 See the release notes (https://confluence.atlassian.com/servicemanagement/jira-service-management-release-notes-780083086.html). You can download the latest version of Jira Service Management Data Center from the download center (https://www.atlassian.com/software/jira/service-management/download-archives). This vulnerability was reported via our Penetration Testing program.
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Analysis
by VulDB Data Team • 09/15/2026
The identified security flaw represents a critical Improper Authorization weakness within Atlassian Jira Service Management Data Center, specifically affecting versions starting from 11.3.0 up to the fixed releases. This vulnerability is classified as High severity with a Common Vulnerability Scoring System score of 7.1, indicating that it poses a significant risk to system integrity and confidentiality. The core technical issue stems from insufficient access control mechanisms in the application logic, which fails to properly verify whether an authenticated user has the necessary permissions to perform specific actions or access certain resources. This misalignment between user identity and authorized capabilities allows attackers who have valid credentials for lower-privileged accounts to escalate their privileges or bypass intended restrictions.
From a technical perspective, this flaw aligns with CWE-269, which describes Improper Privilege Management, where the software does not properly assign privileged functions to execute only on inputs that are within acceptable bounds. In the context of Jira Service Management Data Center, this likely involves endpoints or API calls related to service desk configurations, customer permissions, or internal administrative settings being accessible without adequate verification of the requester's role. An authenticated attacker can exploit this by crafting specific HTTP requests that target these unprotected entry points. Because the authorization check is either missing or incorrectly implemented, the server processes the request as if it originated from a user with higher privileges, such as an administrator or project lead.
The operational impact of this vulnerability extends beyond simple data exposure. While the primary consequence is the unauthorized access to sensitive resources and functionality, which could include viewing private customer information, modifying service desk settings, or accessing internal workflows, there is also potential for more severe outcomes depending on the specific implementation details. In some scenarios involving improper authorization in web applications, this can lead to Server-Side Request Forgery or even arbitrary code execution if the exposed functionality interacts with underlying system components in an unsafe manner. Attackers could leverage this access to exfiltrate confidential data from multiple projects, disrupt service operations by altering configurations, or use the compromised instance as a pivot point for further network intrusion.
This vulnerability maps directly to several techniques within the MITRE ATT&CK framework, particularly those related to privilege escalation and unauthorized access. It corresponds to T1078 Valid Accounts, where attackers leverage legitimate credentials that have been misconfigured or exploited due to poor authorization controls. Furthermore, if the exploitation leads to data theft, it aligns with T1530 Data from Local System, as the attacker gains access to stored information they are not supposed to see. The ability to modify system settings could also relate to T1222 File and Directory Permissions Modification, allowing attackers to alter permissions on files or directories within the application environment to maintain persistence or facilitate further attacks.
Atlassian has acknowledged this issue and released patches in subsequent versions of Jira Service Management Data Center. Customers running version 11.3 are advised that they must upgrade to a release greater than or equal to 11.3.11 to mitigate this risk. For organizations unable to immediately move to the latest stable release, upgrading to one of the specified supported fixed versions is critical. The recommended path involves accessing the Atlassian download center and reviewing the specific release notes for Jira Service Management version 780083086 or later to ensure all security patches are applied. This vulnerability was discovered through responsible disclosure via a penetration testing program, highlighting the importance of regular security assessments in identifying such logic flaws that automated scanners might miss due to their reliance on valid authentication tokens.
To mitigate this risk effectively, organizations should prioritize patching as soon as possible after verifying compatibility with existing integrations and plugins. In addition to upgrading, administrators should review access control policies within Jira Service Management Data Center to ensure the principle of least privilege is strictly enforced across all user roles. Regular audits of user permissions and monitoring for anomalous activity patterns can help detect potential exploitation attempts in real-time. Security teams should also consider implementing Web Application Firewalls with rules tailored to detect abnormal authorization bypass attempts, providing an additional layer of defense while patching efforts are underway. Continuous integration of security testing into the development lifecycle will further reduce the likelihood of similar improper authorization flaws being introduced in future updates.