What is CVE-2026-21570?

CVE-2026-21570 is a high-severity vulnerability in Atlassian Bamboo, classified under Code Injection. CVSS score: 8.8/10. Published 2026-03-17.

How severe is CVE-2026-21570?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Atlassian Bamboo

CVE-2026-21570

This High severity RCE (Remote Code Execution) 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 8.6, allows an authenticated attacker to execute malicious code on the remote system. 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: Upgrade to a release greater than or equal to 9.6.24 Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.16 Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.3 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 Atlassian (Internal) program.

Vulnerability class: RCE (Remote Code Execution)

Published 2026-03-17 · last modified 2026-08-10.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.3th percentile), scored 2026-10-18.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

Atlassian Bamboo
Atlassian Bamboo Data Center — versions 12.1.0 to 12.1.2, 12.0.0 to 12.0.2, 11.0.0 to 11.0.8

Weakness classification (CWE)

CWE-94 — Code Injection

References

confluence.atlassian.com/pages/viewpage.action (Vendor Advisory)
jira.atlassian.com/browse/BAM-26342 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21570?: CVE-2026-21570 is a high-severity vulnerability in Atlassian Bamboo, classified under Code Injection. CVSS score: 8.8/10. Published 2026-03-17.
How severe is CVE-2026-21570?: High severity. CVSS v3 base score is 8.8 out of 10.