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TI-2026-38776 Aliases CVE-2026-53779GHSA-pv77-wrq6-gq73

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

Priority MEDIUM 44CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-22 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00587 48th percentileScored 2026-11-07
Fix Fixed webp_server_go (webp-sh): 0.15.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
webp-shwebp_server_gobefore 0.15.00.15.0Patch availableCNA
  • webp_server_go Vendorwebp-sh Affected before 0.15.0 Fixed in 0.15.0 Patch available CNA

Remediation

  • Fix · CNA webp_server_go (webp-sh) Fixed in 0.15.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53779
  2. 2026-10-03 Alias added: GHSA-pv77-wrq6-gq73

References

Patch 2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences