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CVE Record

CVE-2021-39126: Affected versions of Atlassian Jira Server and Data Center allow remote attackers to modify various resourc...

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to modify various resources via a Cross-Site Request Forgery (CSRF) vulnerability, following an Information Disclosure vulnerability in the referrer headers which discloses a user's CSRF token. The affected versions are before version 8.5.10, and from version 8.6.0 before 8.13.1.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw affects Atlassian Jira Server and Jira Data Center. A remote attacker could misuse a leaked CSRF token from referrer headers to change Jira resources through a victim user’s browser context. The sources do not provide CVSS, confirmed exploitation, or detailed impact boundaries.

Executive priority

Treat this as a time-bound remediation item for affected self-managed Jira. It is not KEV-listed in the provided data, but Jira commonly contains sensitive project and operational workflows, so unauthorized resource changes can create business disruption.

Technical view

CVE-2021-39126 is a CSRF vulnerability tied to information disclosure of a user CSRF token in referrer headers. Affected Jira Server and Data Center versions are before 8.5.10, and 8.6.0 through before 8.13.1. The public record says attackers may modify various resources but does not enumerate them.

Likely exposure

Exposure is limited to organizations running affected Atlassian Jira Server or Data Center versions. Cloud products are not named in the provided sources. Internet-facing Jira instances and environments with many authenticated users likely carry higher business risk.

Exploitation context

The source bundle does not show CISA KEV listing or cite active exploitation. The attack requires a disclosed user CSRF token and a CSRF path to resource modification; the public source does not provide exploit maturity or attacker prevalence.

Researcher notes

The evidence is sparse: no CVSS vector, CWE, exploit status, or resource list is provided. Analysis should stay anchored to Atlassian’s issue and CVE records. Avoid broad claims beyond Jira Server/Data Center and the stated affected version ranges.

Mitigation direction

  • Upgrade Jira Server/Data Center to 8.5.10, 8.13.1, or later.
  • Review Atlassian JRASERVER-71806 for vendor-specific guidance.
  • Prioritize externally reachable Jira instances and high-privilege user populations.
  • Restrict Jira exposure while upgrade planning is underway.
  • Monitor for unexpected Jira resource changes by user accounts.

Validation and detection

  • Inventory Jira Server and Data Center versions across all environments.
  • Flag versions before 8.5.10 and 8.6.0 through before 8.13.1.
  • Confirm cloud-hosted or unrelated Atlassian products are not assumed affected.
  • Review audit logs for unexplained resource modifications around exposure windows.
  • Check whether referrer handling controls exist, without treating them as a vendor fix.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-39126 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AtlassianJira Serverunspecified, 8.6.0, unspecifiedListed
AtlassianJira Data Centerunspecified, 8.6.0, unspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.