perber LeafWiki up to 0.12.0 Zip Extraction zip_extractor.go ZipExtractor.ExtractToDir data amplification

Summaryinfo

A vulnerability, which was classified as problematic, has been found in perber LeafWiki up to 0.12.0. Affected by this issue is the function ZipExtractor.ExtractToDir of the file internal/importer/zip_extractor.go of the component Zip Extraction. This manipulation causes data amplification. This vulnerability appears as CVE-2026-80189. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability has been found in perber LeafWiki up to 0.12.0 and classified as problematic. Affected by this vulnerability is the function ZipExtractor.ExtractToDir of the file internal/importer/zip_extractor.go of the component Zip Extraction. The manipulation with an unknown input leads to a data amplification vulnerability. The CWE definition for the vulnerability is CWE-409. The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-80189 since 08/26/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 0.12.1 eliminates this vulnerability.

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Productinfo

Type

• Content Management System

Vendor

• perber

Name

• LeafWiki

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12.0

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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