Atlassian Data Center arbitrary file access (all DC products, in-the-wild, KEV) — file disclosure on the platforms AI coding agents and RAG pipelines read from

CISA added CVE-2026-21589 to KEV on 2026-10-15 (confirmed in-the-wild exploitation; federal due date 2026-10-18). All versions of Bitbucket, Confluence, Jira SM, Jira Software, Bamboo, Crowd, Crucible and Fisheye Data Center are affected: an unauthenticated attacker who knows a file's exact name/path can access files within the web-application root. Atlassian rates it Critical (CVSS 9.3 v4.0) and states the affected Data Center products 'require immediate attention'. Verified directly against the Atlassian advisory (published 2026-10-05, KEV 2026-10-15).

This is a developer-tooling KEV target with confirmed exploitation, and the affected products are exactly the systems AI coding agents (which read Bitbucket/Jira/pull-request context) and AI-assistant/RAG knowledge bases (which index Confluence spaces) are wired into. Unauthenticated file access in the web-app root can expose configuration files and embedded secrets that AI integration credentials depend on, and a compromised Confluence/Jira instance becomes a high-trust data source an AI agent will naively read — an indirect-prompt-injection and credential-exfiltration amplifier for any AI deployment layered on top of it.

An unauthenticated attacker can access specific files within the web-application root directory of the affected Data Center instance by requesting the exact file name and path (no enumeration possible). In some configurations sensitive files (including files that AI/RAG tooling and integrations read credentials from) are present, increasing risk; fixed via patch, WAF path-traversal regex block, or Tomcat RewriteValve/urlrewrite rule.

Atlassian Data Center products — all versions affected until patched (Bitbucket, Confluence, Jira SM, Jira Software, Bamboo, Crowd, Crucible, Fisheye all versions prior to listed fix versions)

Patch to fixed versions (e.g. Bitbucket 9.4.26/10.2.8/10.5.1, Confluence 9.2.26/10.2.19, Jira 9.12.40/10.3.26/11.3.12, Bamboo 10.2.24/12.1.12, Crowd 6.3.7+/7.x, Crucible/Fisheye 4.9.15), per the Atlassian advisory; until then remove the instance from the internet or apply the WAF/Tomcat path-traversal blocking mitigations listed in the advisory.