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Fencer Intel
medium 5.3

CVE-2021-26086 kev in the critical feed json

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerabili…

published 5y ago modified 4mo ago also EUVD-2021-12907

cvss
5.3
version 3.1, CNA
cisa kev
Exploited
added 2024-11-12
epss
100.0%
EPSS 100.0% chance of exploitation in 30 days, percentile 99.9%
public exploits
1
Exploit-DB, plus a Nuclei check

Summary

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.

Patch / fix

cisa required action Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

  • Atlassian Jira Server 8.5.14, 8.13.6, 8.16.1
  • Atlassian Jira Data Center 8.5.14, 8.13.6, 8.16.1
  • atlassian jira_server 8.5.14, 8.13.6, 8.16.1
  • atlassian jira_data_center 8.5.14, 8.13.6, 8.16.1

Is CVE-2021-26086 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Timeline

  1. Published
  2. First public exploit (EDB-50380)
  3. Added to CISA KEV
  4. CISA SSVC: exploitation active
  5. CISA patch deadline

Known exploited

Added
last yr.
Patch by
2024-12-03 (last yr.)
Ransomware
Not known
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Vendor, product
Atlassian, Jira Server and Data Center
CISA name
Atlassian Jira Server and Data Center Path Traversal Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

100.00% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-50380 Atlassian Jira Server Data Center 8.16.0 - Arbitrary File Read webapps, 2021-10-06
  • Nuclei template Atlassian Jira Limited - Local File Inclusion nuclei detection template
  • packetstormsecurity.com http://packetstormsecurity.com/files/164405/Atlassian-Jira-Server-Data-Center-8.4.0-File-Read.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • Atlassian Jira Server
  • Atlassian Jira Data Center
  • atlassian jira_server
  • atlassian jira_data_center

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.