CVSS 4.0
6.9 mediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:NCVE-2026-63499
Medium (6.9). EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
zt-zip is a Java library that provides convenience methods for ZIP archive manipulation. Prior to 1.18.1, ZipUtil.unpack(...) can apply stored ZIP-entry permissions to the extraction output directory when an entry name such as / or ./ resolves to that directory itself. Because the path traversal checks permit self-referencing entries that do not escape the destination, the unpacker's permission-handling path can replace restrictive output-directory permissions with attacker-supplied permissions. This affects applications that unpack untrusted ZIP files, and POSIX systems demonstrate the issue directly, while ZTFilePermissionsUtil.fetchDefaultStrategy provides fallback permission handling on other supported systems. This issue is fixed in version 1.18.1.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 21st percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: partial, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-23 Relative Path Traversal
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Modified
- Record from
- the NVD, synced
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Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| zeroturnaround zt-zip | < 1.18.1 |
Attack patterns (CAPEC)
- CAPEC-76 Manipulating Web Input to File System Calls Likelihood: High · Severity: Very High
- CAPEC-139 Relative Path Traversal Likelihood: High · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.