9.4

CVE-2026-21571: atlassian bamboo

Analyzed
Published 21-04-2026Last modified 23-04-2026

Vulnerability summary

CVE-2026-21571 is a critical (CVSS 9.4) vulnerability in atlassian bamboo. EPSS estimates a 1.34% chance of exploitation in the next 30 days, higher than 71.4% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.4 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.4/10
010
Critical · v4.0 (CVE.org)
EPSS score
1.34%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 21-04-2026
    PublishedVulnerability first disclosed.
  2. 23-04-2026
    Last modifiedVulnerability information updated.

Description

This 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]).

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.34%

Chance of exploitation in the next 30 days

Percentile

71%

Versus all other CVEs

30-day change

No change 0.00 pp

From 1.34% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Atlassian2 products
  • bamboo≥ 9.6.2, < 9.6.25 | ≥ 10.0.0, < 10.2.18 | ≥ 11.0.0, < 12.1.6
  • bamboo data center12.1.0 to 12.1.3 | 12.0.0 to 12.0.2 | 11.0.0 to 11.0.8 | 10.2.0 to 10.2.16 | 10.1.0 to 10.1.1 | 10.0.0 to 10.0.3 | 9.6.2 to 9.6.24

1 vendor · 2 products

References

2 links