CVE-2021-26086
Atlassian Jira Server / Data Center · Collaboration, telephony and video conferencing
Atlassian Jira Server and Data Center Path Traversal Vulnerability
At a glance
Exploited. Added to CISA’s catalog of exploited vulnerabilities on November 12, 2024.
Affected product: Atlassian Jira Server / Data Center (category Collaboration, telephony and video conferencing, indicative classification). Name in CISA’s catalog: Atlassian Jira Server and Data Center.
What should I do?
Apply the patches or mitigations from Atlassian; if none are available, stop using the product.
Deadline set by CISA for US federal agencies: 21 days (due December 3, 2024). It only binds those agencies, but it is a useful measure of urgency.
- Atlassian security advisories page (general page, not the advisory for this vulnerability)
- The vendor’s specific advisory is listed in the NVD references: CVE-2021-26086 on the NVD website.
Original text of the required action (CISA)
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Timeline
- Vulnerability published Publication date (NVD)
- Exploitation confirmed Added to CISA’s KEV catalog
- CISA deadline Remediation deadline set for US federal agencies
The facts, with their sources
- Exploitation confirmed
- Yes, on November 12, 2024 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Ransomware
- No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Hunt for compromise
- Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA required action
- Apply the patches or mitigations from Atlassian; if none are available, stop using the product. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA deadline
- December 3, 2024, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Vulnerability published
- August 16, 2021 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
- Product according to CISA
- Atlassian Jira Server and Data Center Filed by this site under “Collaboration, telephony and video conferencing” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Severity and activity
FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.
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.
Official description from the NVD, collected Sep 29, 2026. CVE® description © The MITRE Corporation.
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.
Summary from CISA (KEV catalog).
CERT-FR advisories
No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.
Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.
Sources for this page
- CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
- NVD (NIST): CVSS severity, publication date, description, vendor references.
- EPSS (FIRST): probability of exploitation.
- CERT-FR: advisories and alerts (in French).
- Brand and category: indicative classification by this site (method).