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CVE-2026-84939VulnerabilityPublished 09/10/2026Updated 10/17/2026

Libfreemarker java: Path traversal vulnerability in Apache FreeMarker template loading mechanism, if the attacker can specify an arbitrary malformed locale identifier… (CVE-2026-84939)

Affects libfreemarker-javaSource GCVE Database

0

Not known to be exploited · CVSS 9.1 Medium · fixed in 2.3.35 : update libfreemarker-java when convenient.

Data as of 10/25/2026, 16:58:57 UTC

CVSS 3.1 base score
9.1Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 2.3.35
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
Mavenorg.apache.freemarker/freemarkerpkg:maven/org.apache.freemarker/freemarkerOther threatsAffected
  • >=2.2.0 <2.3.35
Fixed in
  • 2.3.35
Ubuntu:16.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=xenialOther threatsAffected
  • =2.3.23-1
  • =2.3.23-2
  • =2.3.23-3
Fixed in–
Ubuntu:18.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=bionicOther threatsAffected
  • =2.3.23-6
  • =2.3.23-7
  • =2.3.23-8
Fixed in–
Ubuntu:20.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=focalOther threatsAffected
  • =2.3.23-9
Fixed in–
Ubuntu:22.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=jammyOther threatsAffected
  • =2.3.23-11
Fixed in–
Ubuntu:24.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=nobleOther threatsAffected
  • =2.3.31-2
  • =2.3.32-1
  • =2.3.32-2
Fixed in–
Ubuntu:26.10libfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=stonkingOther threatsAffected
  • =2.3.32-2.1
Fixed in–
Ubuntu:26.04:LTSlibfreemarker-javapkg:deb/ubuntu/libfreemarker-java?arch=source&distro=resoluteOther threatsAffected
  • =2.3.32-2.1
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Apache FreeMarker to version 2.3.35 or later, where this vulnerability is fixed. Alternatively, disable localized lookup in affected versions to mitigate the issue. No other specific mitigations are indicated. Since this is not a cloud service, remediation depends on user action.

Description

A path traversal vulnerability exists in Apache FreeMarker's template loading mechanism when an attacker can specify a malformed locale identifier and localized lookup is enabled (enabled by default). This affects versions from 2.2.0 through 2.3.34. The vulnerability allows unauthorized access to files within the constraints of the configured TemplateLoader. Users should upgrade to version 2.3.35 or disable localized lookup to mitigate the issue.

Impact

Successful exploitation can lead to unauthorized reading of files accessible to the FreeMarker TemplateLoader, potentially exposing sensitive information. The impact is high confidentiality loss but does not affect integrity or availability. The vulnerability has a CVSS score of 9.1, indicating critical severity in terms of confidentiality impact. However, the actual file access is constrained by the TemplateLoader's configuration and underlying storage mechanism.

Weaknesses

  • CWE-23Relative Path Traversal (opens in a new tab)

    Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)

    The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.

References

Community reviews

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