CVE-2026-44264: Weblate Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-5cmv-3rc4-7279
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CVSS 4.3
CWE-80 CWE-79
Published
Advisory Summary

CVE-2026-44264 is a MODERATE (CVSS 4.3) cross-site scripting vulnerability (CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)) affecting Weblate libraries in the PyPI ecosystem. The issue involves weblate vulnerable to xss via crafted markdown. Remediation is available by upgrading affected packages to version 5.17.1.

CVE-2026-44264 at a Glance

CVE Identifier CVE-2026-44264
GHSA Identifier GHSA-5cmv-3rc4-7279
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
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:N/I:L/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 None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-44264

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: 5.17.1 
pip install weblate>=5.17.1
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-2026-44264, 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 5.17.1), 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-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS), where the product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. 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 The Markdown renderer used in user comments and other user-provided content didn't properly sanitize some attributes. ### Patches * https://github.com/WeblateOrg/weblate/pull/19259 ### Workarounds Even though the attacker might be able to inject code into the HTML, the Weblate's strict CSP should mitigate the risks. ### Acknowlegement Michal Čihař has identified and fixed this vulnerability.

CVE-2026-44264 Affected Weblate Versions

1 component(s)
Fixed Versions:
5.17.1
Product / Package Ecosystem Affected Versions Fixed Version
weblate
pypi/weblate
PyPI
< 5.17.1
5.17.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/WeblateOrg/weblate/security/advisories/GHSA-5cmv-3rc4-7279
NVD — CVE-2026-44264 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44264
Weblate Source Repository REPOSITORY
https://github.com/WeblateOrg/weblate/pull/19259
Security Fix Commit FIX COMMIT
https://github.com/WeblateOrg/weblate/commit/85abc9df88b7464f4c0e794aef752e45f4230f75
Weblate Source Repository REPOSITORY
https://github.com/WeblateOrg/weblate
Weblate Release RELEASE
https://github.com/WeblateOrg/weblate/releases/tag/weblate-5.17.1

Frequently Asked Questions

What is CVE-2026-44264?
CVE-2026-44264 is a security vulnerability in Weblate involving Weblate vulnerable to XSS via crafted Markdown under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS).
Which Weblate versions are affected?
Affected versions include releases prior to 5.17.1 across affected packages: weblate.
What version fixes CVE-2026-44264?
Upgrading to 5.17.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is weblate affected?
Yes, weblate is affected in releases prior to 5.17.1. Upgrade your dependency to 5.17.1 or later.
What is the CVSS score of CVE-2026-44264?
CVE-2026-44264 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:N/I:L/A:N.
What CWE is associated with CVE-2026-44264?
CVE-2026-44264 is classified under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) (The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.).
How can I check PyPI dependencies for CVE-2026-44264?
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-5cmv-3rc4-7279",
  "modified" : "2026-05-08T21:47:44Z",
  "published" : "2026-05-07T00:04:26Z",
  "aliases" : [ "CVE-2026-44264" ],
  "summary" : "Weblate vulnerable to XSS via crafted Markdown",
  "details" : "### Impact\nThe Markdown renderer used in user comments and other user-provided content didn't properly sanitize some attributes.\n\n### Patches\n* https://github.com/WeblateOrg/weblate/pull/19259\n\n### Workarounds\nEven though the attacker might be able to inject code into the HTML, the Weblate's strict CSP should mitigate the risks.\n\n### Acknowlegement\nMichal Čihař has identified and fixed this vulnerability.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "weblate"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.17.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/security/advisories/GHSA-5cmv-3rc4-7279"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44264"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/pull/19259"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/commit/85abc9df88b7464f4c0e794aef752e45f4230f75"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/WeblateOrg/weblate"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WeblateOrg/weblate/releases/tag/weblate-5.17.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79", "CWE-80" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-07T00:04:26Z",
    "nvd_published_at" : "2026-05-07T15:16:10Z"
  }
}