Path Traversal Vulnerability in WebP Server Go on Windows by WebP
CVE-2026-53779

8.7HIGH

Key Information:

Vendor

Webp-sh

Status
Webp Server Go
Vendor
CVE Published:
22 June 2026

What is CVE-2026-53779?

The WebP Server Go version up to 0.14.4 is affected by a path traversal vulnerability on Windows. This issue permits unauthenticated attackers to access files outside the designated IMG_PATH directory by submitting requests that include percent-encoded backslashes (%5C), circumventing the path.Clean() sanitization process. The vulnerability arises from the inconsistency between Go's path normalization using forward slashes and the Windows file system's treatment of backslashes as equivalent. As a result, this flaw can enable attackers to gain unauthorized access to arbitrary files present on the server's filesystem.

Affected Version(s)

webp_server_go 0

References

https://github.com/webp-sh/webp_server_go/pull/451
issue-tracking
https://github.com/webp-sh/webp_server_go/commit/eb3b5f92...
patch
https://www.vulncheck.com/advisories/webp-server-go-path-...
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Katriel Moses
.