CVE-2026-28807

HIGH EPSS 60.2%
Published Mar 10, 20263mo ago · Modified May 27, 20261mo ago
8.7 CVSS 4.0
High
Find Similar
Published Mar 10, 2026 3mo ago
Last Modified May 27, 2026 1mo ago

Description

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal. The wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read. An unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files. This issue affects wisp: from 2.1.1 before 2.2.1.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
60.2% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-22 Path Traversal Resource Mgmt

Affected Products 1

VendorProductVersionRange
gleam-wispwisp*≥2.1.1  –  <2.2.1

References 4

  • cna.erlef.org https://cna.erlef.org/cves/CVE-2026-28807.html
    Third Party Advisory
  • github.com https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fdd93
    Patch
  • github.com https://github.com/gleam-wisp/wisp/security/advisories/GHSA-h7cj-j2vv-qw8r
    ExploitVendor AdvisoryPatch
  • osv.dev https://osv.dev/vulnerability/EEF-CVE-2026-28807
    Third Party Advisory

Remediation

  • github.com https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fdd93
    Patch
  • github.com https://github.com/gleam-wisp/wisp/security/advisories/GHSA-h7cj-j2vv-qw8r
    ExploitVendor AdvisoryPatch