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CVE-2019-3396

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Atlassian Confluence Server and Data Server. For every flaw being used in attacks, see Exploited flaws; for Atlassian’s, see Atlassian flaws being used in attacks.

CVE-2019-3396 is a security flaw in Atlassian Confluence Server and Data Server, a wiki companies use for internal documents. Attackers can run their own code on Atlassian Confluence Server and Data Server. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021, and says ransomware gangs have used it.[1]

Atlassian Confluence Server and Data Server is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 6.6.12, unspecified, 6.12.3 and 6.13.3 and others of Confluence Server.

Description

CISA calls it a confluence server and data center server-side template injection in Atlassian Confluence Server and Data Server. In its words: “Atlassian Confluence Server and Data Center contain a server-side template injection vulnerability that may allow an attacker to achieve path traversal and remote code execution.”[1]

The CVE record adds: “The Widget Connector macro in Atlassian Confluence Server before version 6.6.12 (the fixed version for 6.6.x), from version 6.7.0 before 6.12.3 (the fixed version for 6.12.x), from version 6.13.0 before 6.13.3 (the fixed version for 6.13.x), and from version 6.14.0 before 6.14.2 (the fixed version for 6.14.x), allows remote attackers to achieve path traversal and remote code execution on a Confluence Server or Data Center instance via server-side template injection.”[2]

The underlying weakness is path traversal (CWE-22), in MITRE’s list of common software weaknesses.

It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]

ProductFixed in
Confluence Server6.6.12
Confluence Serverunspecified
Confluence Server6.12.3
Confluence Server6.13.3
Confluence Server6.14.2

Most families won’t have Atlassian Confluence Server and Data Server; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 954 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 May 2022 to fix it.[1] CISA says ransomware gangs have used it.

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at over 99%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as automatable: attackers can run it against many targets at once.

CISA doesn’t say who was attacked, or how.

Fix

Atlassian has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Check whether you use it.Atlassian Confluence Server and Data Server is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
  2. Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 6.6.12, unspecified, 6.12.3 and 6.13.3 and others of Confluence Server), or not in use. CISA gave US government agencies until 3 May 2022 to fix it.
  3. If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.

You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at over 99%.[4]

See also

Other Atlassian flaws

  • CVE-2026-21589, Atlassian products: files or directories accessible to external parties ·
  • CVE-2021-26086, Atlassian Jira Server and Data Center: path traversal ·
  • CVE-2023-22527, Atlassian Confluence Data Center and Server: template injection ·
  • CVE-2023-22518, Atlassian Confluence Data Center and Server: improper authorization ·
  • CVE-2023-22515, Atlassian Confluence Data Center and Server: broken access control ·

Other path traversal flaws

  • CVE-2025-61624, Fortinet products: path traversal ·
  • CVE-2021-3199, ONLYOFFICE Docs: server path traversal ·
  • CVE-2026-104286, Fortinet FortiMail: path traversal ·
  • CVE-2026-93616, Check Point products: path traversal ·
  • CVE-2026-66384, JFrog Artifactory: improper limitation of a pathname to a restricted directory ·

Added the same day

  • CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
  • CVE-2021-42013, Apache HTTP Server: path traversal ·
  • CVE-2021-41773, Apache HTTP Server: path traversal ·
  • CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
  • CVE-2021-40444, Microsoft MSHTML: remote code execution ·

Every Atlassian flaw on CISA’s list · Everything added in November 2021

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Atlassian Confluence Server and Data Center Server-Side Template Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
  2. ^ National Institute of Standards and Technology. “CVE-2019-3396 Detail”. National Vulnerability Database, published 25 Mar 2019.
  3. ^ Atlassian. Advisories and fixes: jira.atlassian.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.999, percentile 100.0, 31 Oct 2026.
  5. CVE Program. “CVE-2019-3396”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.