CVE-2026-78254

Apache Ant: Path traversal in ftp and scp tasks allows arbitrary file write

Published Sep 7, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
The ftp and scp tasks of Apache Ant can download files from a remote server. A malicious server can provide relative paths that allow it to write outside of the dedicated target directory for the download, making it possible to overwrite files of the attacker's choice using the permissions of the user running Ant in versions prior to Ant 1.10.18.




In order to exploit this vulnerability, the server would either have to be malicious or be subject to a machine-in-the-middle attack. Additionally in the case of scp or the ftp task using ftps the server must pass the server identity checks performed by the tasks.




For ftp tasks not using ftps a malicious server could act as a machine-in-the-middle to provide malicious files.




Starting with Ant 1.10.18 both tasks will prevent writing outside of the destination directory by default. An option is available to disable this behavior in the unlikely case that the old behavior is required by existing build files.




Mitigations:




Users of scp and ftp (when using ftps) in any version of Ant should not bypass server identity checks. Users of ftp not using ftps should switch to ftps where possible.




All users are recommended to upgrade to Apache Ant 1.10.18, which fixes this issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
CPEs cpe:2.3:a:apache:ant:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Apache
Apache ant
Vendors & Products Apache
Apache ant
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The ftp and scp tasks of Apache Ant can download files from a remote server. A malicious server can provide relative paths that allow it to write outside of the dedicated target directory for the download, making it possible to overwrite files of the attacker's choice using the permissions of the user running Ant in versions prior to Ant 1.10.18. In order to exploit this vulnerability, the server would either have to be malicious or be subject to a machine-in-the-middle attack. Additionally in the case of scp or the ftp task using ftps the server must pass the server identity checks performed by the tasks. For ftp tasks not using ftps a malicious server could act as a machine-in-the-middle to provide malicious files. Starting with Ant 1.10.18 both tasks will prevent writing outside of the destination directory by default. An option is available to disable this behavior in the unlikely case that the old behavior is required by existing build files. Mitigations: Users of scp and ftp (when using ftps) in any version of Ant should not bypass server identity checks. Users of ftp not using ftps should switch to ftps where possible. All users are recommended to upgrade to Apache Ant 1.10.18, which fixes this issue.
Title Apache Ant: Path traversal in ftp and scp tasks allows arbitrary file write
Weaknesses CWE-23
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Sep 8, 2026, 3:45 PM
Reserved
Aug 24, 2026, 7:17 AM
Status
Analyzed
Published
Sep 7, 2026, 8:17 AM
Modified
Sep 9, 2026, 1:29 PM
Severity
Important
Public date
Sep 7, 2026, 7:41 AM