BambooApplication · Atlassian
CVE-2026-21571
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThis Critical severity OS Command Injection vulnerability was introduced in versions 9.6.0, 10.0.0, 10.1.0, 10.2.0, 11.0.0, 11.1.0, 12.0.0, and 12.1.0 of Bamboo Data Center. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 9.4 and a CVSS Vector of CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H allows an authenticated attacker to execute commands on the remote system, which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction. 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 9.6.0: Upgrade to a release greater than or equal to 9.6.25 Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.18 Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.6 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]).
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOS Command Injection vulnerability in Atlassian Bamboo Data Center allows authenticated attackers with low privileges to execute arbitrary commands on the remote system. The vulnerability affects versions 9.6.0 through 12.1.0 and enables complete remote code execution with high impact to confidentiality, integrity, and availability.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
BambooApplication
>= 9.6.2, < 9.6.25>= 10.0.0, < 10.2.18>= 11.0.0, < 12.1.6CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Bamboo Data Center versionLocate the Bamboo installation directory and check the version file or run the version command (typically found in the 'atlassian-bamboo' directory or via the Bamboo admin console under 'About').Affected if The installed version falls between 9.6.0 and 12.1.0 inclusive.
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Verify Bamboo edition is Data CenterConfirm the installation is the Data Center edition, not the standalone version. This is typically visible in the Bamboo admin console header or 'About' page.Affected if The product is Bamboo Data Center (not standalone) and the version is in the affected range.
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Check if remote agents are enabledReview Bamboo configuration to determine if remote agents are configured. Command injection typically leverages agent-related endpoints.Affected if Remote agents are enabled and the Bamboo version is in the affected range.
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Review user authentication settingsConfirm that low-privilege user accounts exist in the Bamboo user directory. The vulnerability requires an authenticated user with low privileges.Affected if Low-privilege user accounts can be created or exist in the system.
The environment is affected if Bamboo Data Center is installed with a version between 9.6.0 and 12.1.0 inclusive, and low-privilege user authentication is possible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped9.6.2510.2.1812.1.6
Upgrade Bamboo Data Center to version 9.6.25 or higher for 9.6.x, 10.2.18 or higher for 10.2.x, or 12.1.6 or higher for 12.1.x as specified in Atlassian's advisory.
For 9.6.x: upgrade to 9.6.25 or later | For 10.2.x: upgrade to 10.2.18 or later | For 12.1.x: upgrade to 12.1.6 or later (or latest available version)
- 1. Back up your Bamboo Data Center instance, including database and configuration files
- 2. Identify your current Bamboo Data Center version from the administration console
- 3. Determine the appropriate upgrade path based on your current version (9.6.x, 10.2.x, or 12.1.x)
- 4. Download the fixed version from Atlassian download center: https://www.atlassian.com/software/bamboo/download-archives
- 5. Test the upgrade in a staging environment to verify compatibility
- 6. Apply the upgrade to production following Atlassian's upgrade documentation
- 7. Verify the upgrade was successful and the vulnerability is resolved
- 8. Review release notes for any known issues: https://confluence.atlassian.com/bambooreleases/bamboo-release-notes-1189793869.html
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Bamboo
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21571 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21571 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data