@appium/support EUVD-2026-101529

Requires the Appium process (via @appium/support prior to 7.2.6) to extract an attacker-controlled ZIP archive - e.g., a malicious app package, dependency, or bundle processed in a test/CI workflow. The archive must contain a symbolic-link entry resolving outside the extraction directory followed by a regular-file entry whose name resolves through that link; the pre-fix lexical containment check validated only entry names, not symlink targets or real destinations. Limiting factors: UI:R means an operator or automated pipeline must actually trigger extraction of the hostile archive (no fully passive remote trigger), the write is constrained to locations writable by the Appium process, and escalation to code execution additionally requires a sensitive writable target (executable, startup script, or config). Platforms using symlinks (Unix-like) are affected; the vendor regression test skips on Windows.

This is a moderate-risk, defense-in-depth style vulnerability rather than a mass-exploitation emergency. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N = 6.5) tells the real story: although the attack vector is network and requires no privileges, it is gated by UI:R - the Appium process must be induced to extract an attacker-controlled ZIP archive. The impact is scoped narrowly to integrity (C:N/I:H/A:N) because the primitive is an arbitrary file write via symlink-following during extraction (CWE-59), which the advisory notes can escalate to code execution if a writable executable, startup script, or config is overwritten. The 'RCE' tag reflects this downstream potential, not a direct one-shot remote code execution. No EPSS score, no CISA KEV listing, and no public POC were supplied, so exploitation status is: no public exploit identified at time of analysis. The signals are internally consistent - there is no CVSS-vs-reality conflict here - but note the input provides no EPSS probability, so widespread-exploitation likelihood cannot be quantified. This is a 'patch in normal cycle' issue for most, but higher priority for anyone running Appium in shared/CI contexts where it processes externally sourced archives.

An attacker supplies a malicious application package or dependency archive that Appium extracts via @appium/support (for example in a shared test farm or CI pipeline that unzips externally provided app bundles). The archive contains a symlink entry pointing outside the extraction directory followed by a regular file whose name legitimately resolves through that symlink, causing the file to be written to an attacker-chosen location writable by the Appium process. No public exploit was identified at time of analysis, though the fix commit includes a regression test demonstrating the bypass.