Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-78254 is a high-severity Relative Path Traversal (CWE-23) vulnerability in Apache Ant (inferred from references). Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-72281
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Explicit validation of path inputs stops .. sequences from ever being interpreted by the file system.
Access enforcement directly blocks unauthorized file reads/writes that result from unresolved .. sequences.
Information-flow rules can be configured to reject traversals that would move data outside an approved directory boundary.
Least privilege reduces the set of reachable files even when a traversal succeeds.
Secure-engineering principles require safe pathname construction and input neutralization before any file operation.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and path sanitization that prevent relative traversal.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis, but does not itself implement the fix.
Secure development lifecycle mandates input validation and path-handling controls that directly prevent relative path traversal.
Application security requirements explicitly call for controls against path traversal and other injection flaws.
Secure architecture principles include directory isolation and canonicalization, reducing but not eliminating traversal risk.
Secure coding standards require neutralizing path traversal sequences, directly addressing CWE-23.
Information access restriction limits which files can be reached, mitigating impact but not preventing the traversal flaw.