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

> Unauthenticated attackers can access specific files in the web application root directory if they know the exact path, potentially exposing sensitive data.

- **Severity:** Critical 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`)
- **Exploited in the wild:** Yes, since 15 Oct 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-gr66-x5pq-8g2g

## What is CVE-2026-21589?

CVE-2026-21589 is a critical path traversal vulnerability in Atlassian Crucible, published on 5 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

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

## Which versions are affected by CVE-2026-21589?

It affects 10 products.


Products: Atlassian Bamboo, Atlassian Bitbucket Data Center, Atlassian Bitbucket Server, Atlassian Confluence Data Center, Atlassian Crowd, Atlassian Crucible, Atlassian Fisheye, Atlassian Jira Data Center, Atlassian Jira Service Desk, Atlassian Jira Service Management.

## How do I fix CVE-2026-21589?

No fix has been published for CVE-2026-21589 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 18 Oct 2026.

## Is CVE-2026-21589 being exploited?

Yes. Attackers have exploited CVE-2026-21589 in the wild since at least 15 Oct 2026.

Public exploit code:

- https://github.com/watchtowrlabs/watchTowr-vs-Atlassian-CVE-2026-21589 (github_poc): https://github.com/watchtowrlabs/watchTowr-vs-Atlassian-CVE-2026-21589
- CVE-2026-21589 - Atlassian Data Center Unauth Arbitrary File Read (CVSS 9.3). Red/Blue Team suite with 2 tools: Full Exploit (path traversal, WEB-INF read, interactive shell, 8 products, mass scan, SOCKS5/Tor, stealth) and SafeChecker (non-intrusive version audit, WAF detection, IoC guidance, JSON/CSV/JSONL reports). Use Ethically, Stay Legal. (github_poc): https://github.com/tc4dy/CVE-2026-21589-PoC-Exploit
- https://github.com/MarcusProgram/CVE-2026-21589 (github_poc): https://github.com/MarcusProgram/CVE-2026-21589
- CVE-2026-21589 detector for Atlassian Data Center webresource traversal. Pre-auth webroot file read confirm for Jira, Confluence and Bitbucket. (github_poc): https://github.com/ynsmroztas/AtlasSniper
- CVE-2026-21589 — Atlassian DC pre-auth arbitrary file read (CVSS 4.0 9.3). PoCbit PoC: atlassian-plugins-webresource ..:: traversal on /download/resources/ for Jira, Confluence, Bitbucket. check + exploit (WEB-INF/web.xml, crowd.properties). Batch JSONL, hits.txt. Not RCE. https://pocbit.org/pocs/cve-2026-21589 (github_poc): https://github.com/murrez/CVE-2026-21589
- Atlassian Arbitrary File Read (github_poc): https://github.com/gotr00t0day/CVE-2026-21589

## Other vulnerabilities in Atlassian Crucible

- [CVE-2022-26136](https://insights.sbomify.com/CVE-2022-26136/): Auth bypass in Bamboo Data Center (critical 9.8)
- [CVE-2016-5229](https://insights.sbomify.com/CVE-2016-5229/): Deserialization in n/a (critical 9.8)
- [CVE-2014-9757](https://insights.sbomify.com/CVE-2014-9757/): Deserialization in n/a (critical 9.8)
- [CVE-2015-8360](https://insights.sbomify.com/CVE-2015-8360/): Deserialization in n/a (critical 9.8)
- [CVE-2017-14589](https://insights.sbomify.com/CVE-2017-14589/): Code injection in Bamboo (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21589 and fix it if it is affected.

What it is: CVE-2026-21589 is a critical path traversal vulnerability in Atlassian Crucible, published on 5 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-21589 in the wild since at least 15 Oct 2026.

Affected product: Atlassian Crucible. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-21589/ (Markdown: https://insights.sbomify.com/CVE-2026-21589/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21589
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21589
- OSV: https://osv.dev/vulnerability/CVE-2026-21589

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21589/
Summaries are generated and may contain mistakes; the official description above is the record.