Arbitrary file overwrite via Unicode-colliding symlink following
Published Jul 29, 2026 · Updated Jul 29, 2026
Path traversal in Develar app-builder 4.2.0 and earlier allows remote attackers to overwrite arbitrary files during ZIP extraction. The zipx.Unzip routine creates archive-supplied symlinks without checking target containment, then opens regular files without O_NOFOLLOW; APFS can resolve Unicode-colliding names to the planted link. A build must consume the crafted archive, and writes are limited to paths writable by the build user's account.
Summary
What happened
Path traversal in Develar app-builder 4.2.0 and earlier allows remote attackers to overwrite arbitrary files during ZIP extraction. The zipx.Unzip routine creates archive-supplied symlinks without checking target containment, then opens regular files without O_NOFOLLOW; APFS can resolve Unicode-colliding names to the planted link. A build must consume the crafted archive, and writes are limited to paths writable by the build user's account.
The record
- CVE
- CVE-2026-13723
- Published
- Jul 29, 2026
- Updated
- Jul 29, 2026
- Vendor
- Develar
- Product
- app-builder
- Classifications
- CWE-22, CWE-59, T1565.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 29, 2026CVE publishedPublication date reported by the CVE source.
- Jul 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=4.2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- APFS Unicode-collision regression test in pull request 163proof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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