CyberSecBulletin
CVE-2026-34157NVD status: Deferred

wails: Permissive Regular Expression

Published Updated By the CyberSecBulletin desk

CVE-2026-34157 is a high-severity permissive regular expression vulnerability in wails from Wailsapp, with a CVSS 4.0 base score of 7.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected wails versions: >= 2.0.0, < 2.13.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of wails you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Wailsappwails>= 2.0.0, < 2.13.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
PresentThe target must be in a specific state or configuration for the attack to work.
Privileges required
NoneNo account or login is needed.
User interaction
PassiveA user only needs to do something routine, such as viewing a page.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
LowLimited loss of availability on the vulnerable system.
Confidentiality (other systems)
LowLimited loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
LowLimited loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: 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/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. Scored by CNA (github.com).

Official description

Wails is a framework for building desktop applications using Go and web technologies. From 2.0.0 until 2.13.0, BindingsAllowedOrigins in v2/internal/frontend/originvalidator/originValidator.go passes wildcard patterns to wildcardPatternToRegex, which expands every asterisk to an unrestricted regular-expression match. When an application configures a trailing or partial-label wildcard immediately after an allowed domain, an attacker-controlled lookalike origin can match the allowed suffix and invoke bound Go methods through IPC. A complete-component subdomain wildcard is an unaffected configuration. The resulting confidentiality, integrity, and availability impact depends on the file, database, command, credential, or other operations exposed by the application's bound methods. This issue is fixed in version 2.13.0.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Permissive Regular Expression

The product uses a regular expression that does not sufficiently restrict the set of allowed values.

How developers prevent this class of flaw

  • When applicable, ensure that the regular expression marks beginning and ending string patterns, such as /^string$/ for Perl.

More Permissive Regular Expression vulnerabilities (CWE-625)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Permissive Regular Expression vulnerabilities

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