VULNpocalypse

CVE-2026-21589: Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.

What it is

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.

Description quoted from the CVE record (assigned by atlassian, published 2026-10-05).

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

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality high, integrity none, availability none. 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

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.

On CISA KEV since
2026-10-15
US federal deadline
2026-10-18
Ransomware use
Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-16016, EUVD-2026-92807, GHSA-gr66-x5pq-8g2g

VEDAS cluster: VEDAS:FRIGIDFENRIR

Exploit Observer links 18 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (18)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Research and write-ups (8)

Vulnerability databases and vendor advisories (4)

Catalogue entries, not exploit evidence.

News (4)

43 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS
0.995
very likely to be attacked soon
VEDAS
0.987
strong exploit evidence
On CISA KEV
Yes, since 2026-10-15
Detection rule
Nuclei · Suricata
EPSS (chance of attack)
100.1Added to CISA KEV 2026-10-15CVE-2026-21589 EPSS over time2026-102026-11-01
VEDAS (exploit evidence)
100.9Added to CISA KEV 2026-10-15CVE-2026-21589 VEDAS over time2026-102026-11-01

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.

Who is affected

ProductAffectedNot affected
Atlassian Bamboo Data Centerversion All other versionsPatch version 10.2.24 and later is not affected; Patch version 12.1.12 and later is not affected
Atlassian Bitbucket Data Centerversion All other versionsPatch version 10.2.8 and later is not affected; Patch version 10.5.1 and later is not affected; Patch version 9.4.26 and later is not affected
Atlassian Confluence Data Centerversion All other versionsPatch version 10.2.19 and later is not affected; Patch version 9.2.26 and later is not affected
Atlassian Crowd Data Centerversion All other versionsPatch version 7.2.4 and later is not affected; Patch version 7.1.7 and later is not affected; Patch version 7.0.3 and later is not affected; Patch version 6.3.7 and later is not affected
Atlassian Crucible Data Centerversion All other versionsPatch version 4.9.15 and later is not affected
Atlassian Fisheye Data Centerversion All other versionsPatch version 4.9.15 and later is not affected
Atlassian Jira Service Management Data Centerversion All other versionsPatch version 11.3.12 and later is not affected; Patch version 10.3.26 and later is not affected; Patch version 5.12.40 and later is not affected
Atlassian Jira Software Data Centerversion All other versionsPatch version 11.3.12 and later is not affected; Patch version 10.3.26 and later is not affected; Patch version 9.12.40 and later is not affected

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: atlassian bamboo, atlassian bamboo_data_center, atlassian bitbucket_data_center, atlassian bitbucket_server, atlassian confluence_data_center, atlassian crowd, atlassian crowd_data_center, atlassian crucible, atlassian crucible_data_center, atlassian fisheye.

How to fix it

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.

Vendor guidance:

How to detect it

Nuclei template (active check)

Atlassian Jira/Confluence/Bitbucket - Arbitrary File Read

Atlassian products including Jira, Confluence, and Bitbucket Data Center contain a pre-authentication arbitrary file read vulnerability in the shared atlassian-plugins-webresource library. The library improperly handles double colons (::) as path separators in the resource routing, allowing unauthenticated attackers to traverse the filesystem and read arbitrary files within the application server’s webroot, including sensitive configuration files such as web.xml and crowd.properties containing plaintext credentials.

Name and description quoted from the template, written by VEDAS.

The template sends 3 requests (GET /download/resources/jira.webresources:color-picker-popup/images/..:..., GET /s/1/_/download/resources/com.atlassian.confluence.plugins.dashboar..., GET /s/1.0/_/download/resources/com.atlassian.bitbucket.server.bitbucke...); it decides using dsl matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash
nuclei -u https://your-host -t CVE-2026-21589.yaml
Show the template (37 lines)
yaml
id: CVE-2026-21589
info:
  name: "Atlassian Jira/Confluence/Bitbucket - Arbitrary File Read"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    Atlassian products including Jira, Confluence, and Bitbucket Data Center contain a pre-authentication arbitrary file read vulnerability in the shared atlassian-plugins-webresource library. The library improperly handles double colons (::) as path separators in the resource routing, allowing unauthenticated attackers to traverse the filesystem and read arbitrary files within the application server's webroot, including sensitive configuration files such as web.xml and crowd.properties containing plaintext credentials.
  reference:
  - https://www.exploit.observer/?keyword=CVE-2026-21589&match=exact
  - https://subdomain.center/?engine=ammonites&keyword=atlassian&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-21589
    cwe-id: CWE-22
  metadata:
    verified: false
    max-request: 1
  tags: cve,cve2026,atlassian,jira,confluence,bitbucket,lfi,path-traversal,kev,vkev,vuln
http:
- raw:
  - |
    GET /download/resources/jira.webresources:color-picker-popup/images/..::..::..::..::..::WEB-INF::web.xml HTTP/1.1
    Host: {{Hostname}}
  - |
    GET /s/1/_/download/resources/com.atlassian.confluence.plugins.dashboard-actions/images/..::..::..::..::..::..::..::..::WEB-INF::web.xml HTTP/1.1
    Host: {{Hostname}}
  - |
    GET /s/1.0/_/download/resources/com.atlassian.bitbucket.server.bitbucket-webpack-INTERNAL:avatar/avatar/..::..::..::..::..::WEB-INF::urlrewrite.xml HTTP/1.1
    Host: {{Hostname}}
  stop-at-first-match: true
  matchers:
  - type: dsl
    dsl:
    - contains_any(body, "<web-app", "<urlrewrite")
    - status_code == 200
    condition: and

CVE-2026-21589.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-21589 Atlassian Jira/Confluence/Bitbucket - Arbitrary File Read. Add them to your Suricata rule set and reload.

Show the rules
suricata
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-21589 Atlassian Jira/Confluence/Bitbucket - Arbitrary File Read"; flow:established,to_server; http.uri; content:"/download/resources/"; content:"..|3a 3a|"; distance:0; fast_pattern; content:"WEB-INF"; nocase; classtype:web-application-attack; reference:cve,CVE-2026-21589; reference:url,https://www.exploit.observer/?keyword=CVE-2026-21589&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=atlassian&match=exact; sid:1019642; rev:1;)

CVE-2026-21589.rules on GitHub

References

Exploits and technical analysis

Government sources

Other references

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.