---
id: CVE-2026-34157
aliases:
  - GHSA-47hv-j4px-h3c9
title: >-
  Wails: wildcardPatternToRegex allows Origin bypass via suffix match in
  BindingsAllowedOrigins
summary: >-
  Wails: wildcardPatternToRegex allows Origin bypass via suffix match in
  BindingsAllowedOrigins
severity: high
vendor: wailsapp
product: github.com/wailsapp/wails/v2
ecosystem: go
affected:
  - 'github.com/wailsapp/wails/v2 >= 2.0.0, < 2.13.0'
patched:
  - github.com/wailsapp/wails/v2 2.13.0
published: '2026-10-27'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T13:45:03.096294624Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-47hv-j4px-h3c9'
references:
  - url: 'https://github.com/wailsapp/wails/security/advisories/GHSA-47hv-j4px-h3c9'
  - url: 'https://github.com/wailsapp/wails/pull/5074'
  - url: >-
      https://github.com/wailsapp/wails/commit/bcc5941b72fdab6a13942b58871a2696faa85b81
  - url: 'https://github.com/wailsapp/wails'
  - url: 'https://github.com/advisories/GHSA-47hv-j4px-h3c9'
tags:
  - osv
  - go
  - exploit-available
  - ghsa
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/Saku0512/CVE-2026-34157-poc'
  checkedAt: '2026-10-27T16:20:47.579Z'
exploitAvailable: true
cwe:
  - CWE-625
ingestedAt: '2026-10-27T16:11:58.761Z'
---

## Overview

# Security Vulnerability Report: Wails v2 — Origin Validator Bypass via Wildcard Pattern

| | |
|---|---|
| **Product** | wailsapp/wails (v2) |
| **Affected File** | `v2/internal/frontend/originvalidator/originValidator.go` |
| **Affected Versions** | All versions containing originValidator (latest as of 2026-03-26) |
| **CVSSv4.0** | **7.6 HIGH** — `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N` |
| **CWE** | CWE-625: Permissive Regular Expression |
| **Platforms** | Windows / Linux / macOS (all desktop targets) |

---

## Summary

Wails v2 provides `BindingsAllowedOrigins` to restrict which web origins can invoke Go backend methods via IPC. The wildcard pattern matching in `wildcardPatternToRegex` converts `*` to `.*` without anchoring subcomponents, allowing suffix-matched origins to bypass the restriction.

An attacker who controls a domain sharing a prefix with the allowed origin (e.g., `myapp.community` when `myapp.com*` is configured) can invoke arbitrary bound Go methods, potentially achieving file system access, data exfiltration, or code execution depending on the application's exposed API surface.

---

## Vulnerability Details

### Root Cause

`wildcardPatternToRegex` converts a wildcard pattern to a regular expression by escaping special characters and replacing `*` with `.*`. The substituted `.*` has no restriction — it matches any character sequence including dots and additional domain components.

### Vulnerable Code

**File:** `v2/internal/frontend/originvalidator/originValidator.go`

```go
func (v *OriginValidator) wildcardPatternToRegex(wildcardPattern string) string {
    specialChars := []string{"\\", ".", "+", "?", "^", "$", "{", "}", "(", ")", "|", "[", "]"}

    escaped := wildcardPattern
    for _, specialChar := range specialChars {
        escaped = strings.ReplaceAll(escaped, specialChar, "\\"+specialChar)
    }

    // * becomes .* — matches ANY character sequence, including dots and domain separators
    escaped = strings.ReplaceAll(escaped, "*", ".*")

    return "^" + escaped + "$"
}
```

The generated regex for `https://myapp.com*` is:

```
^https://myapp\.com.*$
```

This matches any string beginning with `https://myapp.com`, including:

- `https://myapp.community` — different TLD
- `https://myapp.com.attacker.com` — attacker-controlled subdomain
- `https://myapp.comXXXXX` — any arbitrary suffix

### Scope Note

The official comment in `options.go` gives `https://*.myapp.com` as the example pattern (subdomain prefix wildcard). This pattern is **not affected**. The vulnerability only manifests when developers use a trailing wildcard (`myapp.com*`), which is a natural misuse when intending to permit a domain and all its subpaths or ports.

---

## Impact

Any Go method registered with Wails bindings becomes callable from the attacker's origin. Depending on the application:

- File system read / write (common in desktop apps)
- Database queries
- OS command execution (if exposed via bindings)
- Sensitive configuration or credential access

---

## Fix

**PR:** https://github.com/wailsapp/wails/pull/5074

Wildcards are now only expanded when they represent a full domain component (immediately after `://`, `.`, or `:`). A wildcard appended to a partial label (e.g. `com*`) is stripped, preventing suffix-based bypasses. Comprehensive test suite added.

---

## Disclosure Timeline

| Date | Event |
|---|---|
| 2026-03-26 | Vulnerability discovered during source code audit by @Saku0512 |
| 2026-03-26 | Private report submitted via GitHub Security Advisory |
| 2026-03-26 | Vendor acknowledgement and fix PR opened (#5074) |
| TBD | Patch release |
| TBD + 90 days | Public disclosure deadline |

## Affected packages

- `github.com/wailsapp/wails/v2 >= 2.0.0, < 2.13.0`

## Remediation

Upgrade to a patched release:

- `github.com/wailsapp/wails/v2 2.13.0`