Bug 2531282 (CVE-2026-84939)

Summary:	CVE-2026-84939 org.apache.freemarker/freemarker: Apache FreeMarker: Path traversal via malformed locale identifier
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	ant, aschwart, aszczucz, boliveir, cescoffi, drichtar, ewittman, fmongiar, gmalinko, gsmet, janstey, jmartisk, jnethert, manderse, mposolda, nipatil, olubyans, ozzy, pantinor, pdelbell, pjindal, rguimara, rkubis, rmartinc, rstepani, sbiarozk, ssilvert, sthorger, varjain, vmuzikar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in Apache FreeMarker. A remote attacker could exploit a path traversal vulnerability in the template loading mechanism by providing a specially crafted, malformed locale identifier. This is possible if the localized lookup configuration setting is enabled, which is the default. This vulnerability could allow an attacker to access files outside the intended base directory, potentially leading to information disclosure or unauthorized file access, depending on the configured TemplateLoader.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-10 05:31:16 UTC

Path traversal vulnerability in Apache FreeMarker template loading mechanism, if the attacker can specify an arbitrary malformed locale identifier to FreeMarker, and the localized lookup configuration setting is enabled (it's by default enabled).

This issue affects Apache FreeMarker from 2.2.0 through 2.3.34.

Users are recommended to upgrade to version 2.3.35. Disabling localized lookup in previous versions also mitigates this.

Note that even in versions affected by this vulnerability, the files that can be loaded remain restricted by the TemplateLoader that FreeMarker is configured to use. In particular, FileTemplateLoader prevents attempts to traverse outside the baseDir specified in its constructor. Other TemplateLoader implementations may allow access outside their designated base directory, but they are still constrained by the underlying storage mechanism—for example, a loader wrapping a Java class loader can only access resources that the class loader can load, while one wrapping a web application context can only access resources available through that context.