CVE-2026-42150: wlc Print_html Outputs API Data Without Vulnerability

MODERATE
Advisory Identifier: GHSA-gx2m-mcc2-r4p3
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CVSS 5.1
CWE-79
Published
Advisory Summary

CVE-2026-42150 is a MODERATE (CVSS 5.1) print_html outputs api data without vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting wlc libraries in the PyPI ecosystem. The issue involves print_html outputs api data without html escaping. Remediation is available by upgrading affected packages to version 2.0.0.

CVE-2026-42150 at a Glance

CVE Identifier CVE-2026-42150
GHSA Identifier GHSA-gx2m-mcc2-r4p3
Severity MODERATE
CVSS v3.1 Base Score 5.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product wlc
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required High (PR:H)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-42150

To remediate this vulnerability, upgrade all affected wlc dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

wlc fixed: 2.0.0 
pip install wlc>=2.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show wlc

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-42150, inspect your installed packages using pip:

pip show wlc

Analyze the terminal output to locate any version of wlc in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.0), your application is affected.

Note: The pip show wlc command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In wlc, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The HTML output format in wlc embeds API response data into HTML without escaping, allowing cross-site scripting when the output is rendered in a browser. ### Patches * https://github.com/WeblateOrg/wlc/pull/1327 ### Workarounds The only vulnerable code path is HTML output which is opt-in. ### References Weblate thanks @fg0x0 for reporting this on GitHub.

CVE-2026-42150 Affected wlc Versions

1 component(s)
Fixed Versions:
2.0.0
Product / Package Ecosystem Affected Versions Fixed Version
wlc
pypi/wlc
PyPI
< 2.0.0
2.0.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/WeblateOrg/wlc/security/advisories/GHSA-gx2m-mcc2-r4p3
NVD — CVE-2026-42150 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42150
wlc Source Repository REPOSITORY
https://github.com/WeblateOrg/wlc/pull/1327
Security Fix Commit FIX COMMIT
https://github.com/WeblateOrg/wlc/commit/0f3e58f6d7457b05d48ef40f579a172c4c8b8469
wlc Source Repository REPOSITORY
https://github.com/WeblateOrg/wlc
wlc Release RELEASE
https://github.com/WeblateOrg/wlc/releases/tag/2.0.0

Frequently Asked Questions

What is CVE-2026-42150?
CVE-2026-42150 is a security vulnerability in wlc involving print_html outputs API data without HTML escaping under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which wlc versions are affected?
Affected versions include releases prior to 2.0.0 across affected packages: wlc.
What version fixes CVE-2026-42150?
Upgrading to 2.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is wlc affected?
Yes, wlc is affected in releases prior to 2.0.0. Upgrade your dependency to 2.0.0 or later.
What is the CVSS score of CVE-2026-42150?
CVE-2026-42150 has a CVSS v3.1 base score of 5.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L.
What CWE is associated with CVE-2026-42150?
CVE-2026-42150 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check PyPI dependencies for CVE-2026-42150?
Run the dependency tree command: 'pip show wlc'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gx2m-mcc2-r4p3",
  "modified" : "2026-05-12T13:27:31Z",
  "published" : "2026-04-24T20:43:30Z",
  "aliases" : [ "CVE-2026-42150" ],
  "summary" : "wlc: print_html outputs API data without HTML escaping",
  "details" : "### Impact\nThe HTML output format in wlc embeds API response data into HTML without escaping, allowing cross-site scripting when the output is rendered in a browser.\n\n\n### Patches\n* https://github.com/WeblateOrg/wlc/pull/1327\n\n### Workarounds\nThe only vulnerable code path is HTML output which is opt-in.\n\n### References\nWeblate thanks @fg0x0 for reporting this on GitHub.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "wlc"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/wlc/security/advisories/GHSA-gx2m-mcc2-r4p3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-42150"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/wlc/pull/1327"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/wlc/commit/0f3e58f6d7457b05d48ef40f579a172c4c8b8469"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/WeblateOrg/wlc"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/wlc/releases/tag/2.0.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-24T20:43:30Z",
    "nvd_published_at" : "2026-05-08T04:16:18Z"
  }
}