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Fencer Vulns
high 7.5

CVE-2026-21589 kev in the critical feed json

This is a vulnerability in Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, B…

published 2026-10-05 34 d ago modified 2026-10-29 10 d ago also EUVD-2026-92807

cvss
7.5
version 3.1, NVD
cisa kev
Exploited
added 2026-10-15
epss
99.7%
EPSS 99.7% chance of exploitation in 30 days, percentile 99.9%
public exploits
0
none known, plus a Nuclei check

Summary

This is a vulnerability in Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center. Crowd Data Center, Crucible and Fisheye. This Arbitrary File Access vulnerability allows an unauthenticated attacker to access specific files within the web application root directory in affected versions. Exploitation requires prior knowledge of the target file's exact name and path; this vulnerability does not allow attackers to enumerate or list directory contents. In some configurations, there may be some sensitive files that make this highly severe. This vulnerability allows an unauthenticated remote attacker to access specific files within the web application root directory in affected versions. The vulnerability must be addressed for affected versions of: -- Bitbucket Data Center, introduced in version >= 4.6.0, fix versions: 9.4.26, 10.2.8, 10.5.1 -- Confluence Data Center, introduced in version >= 5.10.0, fix versions 9.2.26, 10.2.19 -- Crowd Data Center, introduced in version >= 2.11.0, fix versions 6.3.7, 7.0.3, 7.1.7, 7.2.4 -- Jira Software Data Center, introduced in version >= 7.1.0, fix versions 9.12.40, 10.3.26, 11.3.12 -- Jira Service Management Data Center, introduced in version >= 3.1.0, fix versions 5.12.40, 10.3.26, 11.3.12 -- Bamboo Data Center >= 7.0.1, fix versions 10.2.24, 12.1.12 -- Crucible, fix versions 4.9.15 -- Fisheye, fix version 4.9.15 -- Exploitation requires prior knowledge of the target file's exact name and path. The vulnerability does not include the capability to enumerate or list directory contents.

Patch / fix

cisa required action Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

  • Atlassian Bamboo Data Center Patch version 10.2.24 and later, Patch version 12.1.12 and later
  • Atlassian Bitbucket Data Center Patch version 9.4.26 and later, Patch version 10.2.8 and later, Patch version 10.5.1 and later
  • Atlassian Confluence Data Center Patch version 9.2.26 and later, Patch version 10.2.19 and later
  • Atlassian Crowd Data Center Patch version 6.3.7 and later, Patch version 7.0.3 and later, Patch version 7.1.7 and later, Patch version 7.2.4 and later
  • Atlassian Crucible Data Center Patch version 4.9.15 and later
  • Atlassian Fisheye Data Center Patch version 4.9.15 and later
  • Atlassian Jira Service Management Data Center Patch version 5.12.40 and later, Patch version 10.3.26 and later, Patch version 11.3.12 and later
  • Atlassian Jira Software Data Center Patch version 9.12.40 and later, Patch version 10.3.26 and later, Patch version 11.3.12 and later

Timeline

  1. Published
  2. Added to CISA KEV
  3. CISA SSVC: exploitation active
  4. CISA patch deadline

Known exploited

Added
25 d ago
Patch by
2026-10-18 (22 d ago)
Ransomware
Not known
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Vendor, product
Atlassian, Multiple Products
CISA name
Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

99.66% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Nuclei template Atlassian Jira/Confluence/Bitbucket - Pre-Auth Arbitrary File Read nuclei detection template
  • github.com https://github.com/watchtowrlabs/watchTowr-vs-Atlassian-CVE-2026-21589 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • Atlassian Bamboo Data Center
  • Atlassian Bitbucket Data Center
  • Atlassian Confluence Data Center
  • Atlassian Crowd Data Center
  • Atlassian Crucible Data Center
  • Atlassian Fisheye Data Center
  • Atlassian Jira Service Management Data Center
  • Atlassian Jira Software Data Center

Classification

Weakness
  • CWE-552 Files or Directories Accessible to External Parties

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.