CVE-2026-80189
MEDIUMCVE-2026-80189 is a medium-severity (CVSS 6.5) CWE-409 vulnerability. O3 Security confirms whether CVE-2026-80189 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
LeafWiki extracts an uploaded ZIP archive without limiting how much data it will write. ZipExtractor.ExtractToDir in internal/importer/zip_extractor.go opens each entry and copies it…
Description
LeafWiki extracts an uploaded ZIP archive without limiting how much data it will write. ZipExtractor.ExtractToDir in internal/importer/zip_extractor.go opens each entry and copies it to the destination with io.Copy, which runs to the end of the decompressed stream, so only the size of the uploaded archive is bounded and the size it expands to is not. The import route that reaches this code requires the Editor or Admin role, and the upload itself is capped at 500 MiB compressed. Because a ZIP entry can compress at a very high ratio, an archive well inside that cap can expand to hundreds of gigabytes as it is written out. The extraction directory defaults to a location under the operating system temporary directory, so the written data consumes the disk backing that path, which on a tmpfs-backed temporary directory is memory. A user holding the Editor role can therefore exhaust the storage the service depends on and keep it from serving, using far more resource than the upload limit alone would permit.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-80189 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-80189 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-80189. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-80189 in your dependencies?
O3 detects CVE-2026-80189 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.