CVE-2026-53779 PUBLISHED

WebP Server Go < 0.15.0 Path Traversal via Backslash Encoding on Windows

Assigner: VulnCheck
Reserved: 10.06.2026 Published: 22.06.2026 Updated: 23.06.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor webp-sh
Product webp_server_go
Versions Default: affected
  • affected from 0 to 0.15.0 (excl.)

Credits

  • Katriel Moses reporter

References

Problem Types

  • Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE