CVE-2026-53779CWE-22

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

High · published June 22, 2026

CVSS v4.0
8.7
EPSS
1%
Percentile
47.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
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
EPSS
0.00587 · 47.4th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-06-22T18:22Z
EPSS history
Timeline
  • 22 JUN 18:22Z
    WebP Server Go < 0.15.0 Path Traversal via Backslash Encoding on Windows
    cvelistv5