# Atlassian Jira Server and Data Center Path Traversal · pwn.watch

> Atlassian Jira Server and Data Center contain a path traversal vulnerability that allows a remote attacker to read particular files in the /WEB-INF/web.xml endpoint. Added to the CISA KEV catalog on 2024-11-12. CVE-2021-26086 was assigned before 2024; the KEV listing came in 2024.

Page: https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086 · generated 2026-10-22T22:54:30.229Z

## Status
- Severity: medium · status: closed · patch: patched
- Product: Atlassian Jira Server and Data Center
- Started: 2024-11-12 · closed: 2024-11-12
- CVEs: CVE-2021-26086
- Affected: See vendor advisory (versions are not listed in the KEV record)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086/feed.xml
- JSON Feed: https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086.json
- This file: https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086/llms.txt

## Updates (newest first)
- 2024-11-12: CISA added CVE-2021-26086 to the KEV catalog (federal deadline 2024-12-03) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)

## Fix brief
# Security brief: Atlassian Jira Server and Data Center Path Traversal

Source: https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086 · status: closed (closed Nov 12, 2024) · severity: medium · updated Nov 12, 2024

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
Atlassian Jira Server and Data Center contain a path traversal vulnerability that allows a remote attacker to read particular files in the /WEB-INF/web.xml endpoint. Added to the CISA KEV catalog on 2024-11-12. CVE-2021-26086 was assigned before 2024; the KEV listing came in 2024.

Severity detail: CVSS 5.3 (v3.1, CISA-ADP), actively exploited (CISA KEV)

- Product: Atlassian Jira Server and Data Center
- CVE / advisory ids: CVE-2021-26086

## Affected versions
- See vendor advisory (versions are not listed in the KEV record)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Nov 12, 2024: CISA added CVE-2021-26086 to the KEV catalog (federal deadline 2024-12-03)

## Advisories
- [Atlassian advisory: CVE-2021-26086](https://jira.atlassian.com/browse/JRASERVER-72695) (Atlassian)
- [NVD: CVE-2021-26086](https://nvd.nist.gov/vuln/detail/CVE-2021-26086) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from the CISA KEV JSON feed (catalogVersion 2026.10.21); CVSS from the CVE record (cveawg.mitre.org). startedAt is the CVE publication date when it fell in 2024 before the KEV listing, else the KEV dateAdded; exploitation may have begun earlier. closedAt is the KEV listing date (a fix or mitigation was available then unless noted).

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Machine-readable: https://pwn.watch/i/atlassian-jira-server-and-data-center-cve-2021-26086.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.