Bug 2529299 (CVE-2026-78254)

Summary: CVE-2026-78254 org.apache.ant/ant: Apache Ant: Arbitrary file write via path traversal in ftp and scp tasks
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: aschwart, aszczucz, boliveir, csutherl, drichtar, dsoumis, ewittman, gbenhaim, gmalinko, janstey, jclere, jwon, mposolda, nipatil, niyer, pantinor, pdelbell, pjindal, plodge, rhel-process-autobot, rjohnson, rkubis, rmartinc, rmaucher, rstepani, ssilvert, sthorger, szappis, twaugh, vmuzikar, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in Apache Ant. The ftp and scp tasks, used for downloading files, are vulnerable to a path traversal issue. A malicious remote server can exploit this by providing specially crafted relative paths, allowing it to write files outside the intended download directory. This could lead to an attacker overwriting arbitrary files on the system with the permissions of the user running Ant, potentially compromising the system's integrity.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2531705, 2531706, 2531709, 2531710, 2531711, 2531712, 2531713, 2531714, 2531715, 2531716, 2531707, 2531708    
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Description OSIDB Bzimport 2026-09-07 07:51:25 UTC 
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.