CVE intelligence and bounded remediation

CVE-2026-53779 — WebP Server Go security vulnerability

High CVSS 8.7

WebP Server Go through 0.14.4 contains a path traversal vulnerability on Windows that allows unauthenticated attackers to read files outside the configured IMG_PATH directory by sending requests with percent-encoded backslashes (%5C) that bypass the path.Clean() sanitization in handler/router.go. Attackers can exploit the discrepancy between Go's forward-slash-only path normalization and Windows file system APIs that treat backslashes and forward slashes as equivalent to access arbitrary files on the host filesystem accessible to the server process.

Severity
High
CVSS
8.7 (4.0)
Published
2026-06-22
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-22

Affected products

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Matched remediation archetype

Path traversal, unsafe upload, and file handling

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Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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