CVE-2026-84939: Path traversal vulnerability in Apache FreeMarker template loading mechanism, if the attacker can specify an a

Q: How do I fix CVE-2026-84939?

freemarker: upgrade to 2.3.35. Exact commands for each OS are on this page.

Q: Is CVE-2026-84939 being exploited?

CVE-2026-84939 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-84939 affect?

CVE-2026-84939 affects freemarker. Severity is critical (CVSS 9.1). 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 ena

Q: How urgent is CVE-2026-84939?

Priority 56/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

This month

CRITICAL 9.1REMOTEWATCHLISTUPGRADE

CVE-2026-84939 is a critical-severity flaw (CVSS 9.1) affecting freemarker. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Critical severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 42%)
CISA exploited list	No
Weakness	CWE-23
Published	2026-09-10
Last modified	2026-09-11

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-10 06:17 UTCPublished CVE record published
2026-09-11 13:06 UTCUpdated Record last modified

apache freemarker UPGRADE

Affected: >= 2.2 and < 2.3.35

Fixed in: 2.3.35

Safe to downgrade to: a release before 2.2

1. Check installed version

apt-cache policy freemarker || rpm -q freemarker || freemarker --version

2. UPGRADE to 2.3.35 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade freemarker

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freemarker

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.2 (Debian / Ubuntu)

apt-cache madison freemarker sudo apt install freemarker=<VERSION_BEFORE_2.2> sudo apt-mark hold freemarker

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list freemarker sudo dnf downgrade freemarker-<VERSION_BEFORE_2.2> sudo dnf versionlock add freemarker

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Maven · org.freemarker:freemarker · FIXED · 2.3.35 · vulnerable: >= 2.2.0, <= 2.3.34 · source

Set org.freemarker:freemarker to 2.3.35 or later in pom.xml or build.gradle, then rebuild and redeploy.

Fedora 46 · ddnet · FIXED · 20.2-1.fc46 · FEDORA-2026-6991b4ab14 · source

sudo dnf upgrade --advisory=FEDORA-2026-6991b4ab14

Fedora ELN · libplacebo · FIXED · 7.360.1-5.eln159 · FEDORA-2026-92226f221e · source

sudo dnf upgrade --advisory=FEDORA-2026-92226f221e

Debian 12 · libfreemarker-java · NO FIX YET

Debian 13 · libfreemarker-java · NO FIX YET

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-84939?

freemarker: upgrade to 2.3.35. Exact commands for each OS are on this page.

Is CVE-2026-84939 being exploited?

CVE-2026-84939 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-84939 affect?

CVE-2026-84939 affects freemarker. Severity is critical (CVSS 9.1). 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 ena

How urgent is CVE-2026-84939?

Priority 56/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

References

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