Unauthenticated file disclosure via path parameter normalization
Published Aug 16, 2021 · Updated Oct 21, 2025
Affected Jira Server and Data Center releases allow remote attackers to read restricted files through a crafted request. Tomcat strips semicolon path parameters and then normalizes parent-directory segments after its restricted-directory check, resolving the path to /WEB-INF/web.xml. No authentication or user interaction is required, but disclosure is limited to particular files reachable through this routing discrepancy.
Summary
What happened
Affected Jira Server and Data Center releases allow remote attackers to read restricted files through a crafted request. Tomcat strips semicolon path parameters and then normalizes parent-directory segments after its restricted-directory check, resolving the path to /WEB-INF/web.xml. No authentication or user interaction is required, but disclosure is limited to particular files reachable through this routing discrepancy.
The record
- CVE
- CVE-2021-26086
- Published
- Aug 16, 2021
- Updated
- Oct 21, 2025
- Vendor
- Atlassian
- Product
- Jira Server
- Classifications
- CWE-22, T1005, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 16, 2021CVE publishedPublication date reported by the CVE source.
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <8.5.14
- Affected versionversion=8.14.0 <8.16.1
- Affected versionversion=8.14.0 <unspecified
- Affected versionversion=8.6.0 <8.13.6
- Affected versionversion=8.6.0 <unspecified
- Affected versionversion=unspecified <8.13.6
- Affected versionversion=unspecified <8.16.1
- Affected versionversion=unspecified <8.5.14
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
View daily counts
| Reporting day | Unique IPs |
|---|---|
| Sep 10, 2026 | 2 |
| Sep 11, 2026 | 2 |
| Sep 12, 2026 | 1 |
| Sep 13, 2026 | 1 |
| Sep 14, 2026 | 1 |
| Sep 15, 2026 | 1 |
| Sep 16, 2026 | 1 |
Weakness, pattern, technique
Public exploit references
- Atlassian Jira Server Data Center 8.4.0 File Readfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog entry for Atlassian Jira path traversalknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
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