CVE-2021-26086
MediumExploitedPublic exploitAffected 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.
Published Oct 15, 2021 · Updated Oct 21, 2025 · Also known as TR-21-0841
Key Facts
Patch immediately- CVE-2021-26086 is a medium-severity vulnerability (CVSS 5.3 v3.1) affecting Jira Data Center (Atlassian), Jira Server (Atlassian).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 26, 2023. Public exploit code is available.
- EPSS estimates a 100% probability of exploitation in the next 30 days.
- Fixed versions are available, including Jira Data Center 8.5.14, Jira Data Center 8.13.6, Jira Data Center 8.16.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS (30-day exploit likelihood)
100%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 12, 2024 | Dec 3, 2024 | Not reported |
| Industry KEV feed | Nov 18, 2023 | Dec 3, 2024 | Not reported |
| CIRCL KEV | Oct 26, 2023 | Dec 3, 2024 | Not reported |
| ENISA EUVD | Nov 12, 2024 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Jira Data CenterAtlassian | >= unspecified | 8.5.14 |
| Jira ServerAtlassian | >= unspecified | 8.5.14 |
Patched Releases
Jira Data Center
8.5.14, 8.13.6, 8.16.1, unspecified
Jira Server
8.5.14, 8.13.6, 8.16.1, unspecified
Timeline
Publicly disclosed
Oct 15, 2021
Added to CIRCL KEV
Oct 26, 2023
Added to Industry KEV feed
Nov 18, 2023
Added to CISA KEV
Nov 12, 2024
Added to ENISA EUVD
Nov 12, 2024
Last updated
Oct 21, 2025
Weakness Type
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
References
- advisoryhttp://jira.atlassian.com/browse/JRASERVER-72695
- advisoryhttp://packetstormsecurity.com/files/164405/Atlassian-Jira-Server-Data-Center-8.4.0-File-Read.html
- advisoryhttps://jira.atlassian.com/browse/JRASERVER-72695
- advisoryhttps://www.cybersecurity-help.cz/exploits/57375/?ref=bulletin
- advisoryhttps://www.cybersecurity-help.cz/vdb/SB2021101419
FAQ
Common Questions.
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.
Affected: Jira Data Center (Atlassian) versions >= unspecified; Jira Server (Atlassian) versions >= unspecified. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 26, 2023.
Yes. It was added on Nov 12, 2024 with a federal remediation due date of Dec 3, 2024.
Public exploit code is available.
Fixed versions are available, including Jira Data Center 8.5.14, Jira Data Center 8.13.6, Jira Data Center 8.16.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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