CVE-2026-27457: Weblate Missing Access Control For The Vulnerability

MODERATE
Advisory Identifier: GHSA-wppc-7cq7-cgfv
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CVSS 4.3
CWE-862 CWE-200
Published
Advisory Summary

CVE-2026-27457 is a MODERATE (CVSS 4.3) missing access control for the vulnerability (CWE-862: Missing Authorization) affecting Weblate libraries in the PyPI ecosystem. The issue involves missing access control for the addonviewset api exposes all addon configurations. Remediation is available by upgrading affected packages to version 5.16.1.

CVE-2026-27457 at a Glance

CVE Identifier CVE-2026-27457
GHSA Identifier GHSA-wppc-7cq7-cgfv
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-862: Missing Authorization
Affected Product Weblate
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.3

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-27457

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

weblate fixed: 5.16.1 
pip install weblate>=5.16.1
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 weblate

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-27457, inspect your installed packages using pip:

pip show weblate

Analyze the terminal output to locate any version of Weblate in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.16.1), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In Weblate, 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 Users were able to obtain add-on configuration via API. ### Patches * https://github.com/WeblateOrg/weblate/pull/18107 * https://github.com/WeblateOrg/weblate/pull/18164 ### References Weblate thanks @lighthousekeeper1212 for responsible disclosure.

CVE-2026-27457 Affected Weblate Versions

1 component(s)
Fixed Versions:
5.16.1
Product / Package Ecosystem Affected Versions Fixed Version
weblate
pypi/weblate
PyPI
< 5.16.1
5.16.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/WeblateOrg/weblate/security/advisories/GHSA-wppc-7cq7-cgfv
NVD — CVE-2026-27457 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27457
Weblate Source Repository REPOSITORY
https://github.com/WeblateOrg/weblate/pull/18107
Weblate Source Repository REPOSITORY
https://github.com/WeblateOrg/weblate/pull/18164
Security Fix Commit FIX COMMIT
https://github.com/WeblateOrg/weblate/commit/3f58f9a4152bc0cbdd6eff5954f9c7bc4d9f0af9
Security Fix Commit FIX COMMIT
https://github.com/WeblateOrg/weblate/commit/7802c9b121eb407c48d4adddd4f2458fb3efef0f
Weblate Source Repository REPOSITORY
https://github.com/WeblateOrg/weblate
Weblate Release RELEASE
https://github.com/WeblateOrg/weblate/releases/tag/weblate-5.16.1

Frequently Asked Questions

What is CVE-2026-27457?
CVE-2026-27457 is a security vulnerability in Weblate involving Missing access control for the AddonViewSet API exposes all addon configurations under CWE-862: Missing Authorization.
Which Weblate versions are affected?
Affected versions include releases prior to 5.16.1 across affected packages: weblate.
What version fixes CVE-2026-27457?
Upgrading to 5.16.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is weblate affected?
Yes, weblate is affected in releases prior to 5.16.1. Upgrade your dependency to 5.16.1 or later.
What is the CVSS score of CVE-2026-27457?
CVE-2026-27457 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-27457?
CVE-2026-27457 is classified under CWE-862: Missing Authorization (The product does not perform an authorization check when an actor attempts to access a resource or perform an action.).
How can I check PyPI dependencies for CVE-2026-27457?
Run the dependency tree command: 'pip show weblate'. 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-wppc-7cq7-cgfv",
  "modified" : "2026-02-27T21:59:14Z",
  "published" : "2026-02-26T19:45:06Z",
  "aliases" : [ "CVE-2026-27457" ],
  "summary" : "Weblate: Missing access control for the AddonViewSet API exposes all addon configurations",
  "details" : "### Impact\n\nUsers were able to obtain add-on configuration via API.\n\n### Patches\n\n* https://github.com/WeblateOrg/weblate/pull/18107\n* https://github.com/WeblateOrg/weblate/pull/18164\n\n\n### References\n\nWeblate thanks @lighthousekeeper1212 for responsible disclosure.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "weblate"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.16.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/security/advisories/GHSA-wppc-7cq7-cgfv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-27457"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/pull/18107"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/pull/18164"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/commit/3f58f9a4152bc0cbdd6eff5954f9c7bc4d9f0af9"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/commit/7802c9b121eb407c48d4adddd4f2458fb3efef0f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/WeblateOrg/weblate"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/releases/tag/weblate-5.16.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-26T19:45:06Z",
    "nvd_published_at" : "2026-02-26T22:20:48Z"
  }
}