{
"document": {
"category": "csaf_base",
"csaf_version": "2.0",
"distribution": {
"tlp": {
"label": "WHITE"
}
},
"lang": "en",
"notes": [
{
"category": "legal_disclaimer",
"text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
}
],
"publisher": {
"category": "coordinator",
"contact_details": "cert@ncsc.nl",
"name": "National Cyber Security Centre",
"namespace": "https://www.ncsc.nl/"
},
"title": "CVE-2026-34231",
"tracking": {
"current_release_date": "2026-04-03T15:26:05.422351Z",
"generator": {
"date": "2026-02-17T15:00:00Z",
"engine": {
"name": "V.E.L.M.A",
"version": "1.7"
}
},
"id": "CVE-2026-34231",
"initial_release_date": "2026-03-30T17:42:03.265237Z",
"revision_history": [
{
"date": "2026-03-30T17:42:03.265237Z",
"number": "1",
"summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)."
},
{
"date": "2026-03-30T17:42:13.840021Z",
"number": "2",
"summary": "NCSC Score created."
},
{
"date": "2026-03-31T16:25:48.815501Z",
"number": "3",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
},
{
"date": "2026-03-31T16:25:51.259322Z",
"number": "4",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-31T16:38:54.886859Z",
"number": "5",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (3).| CWES updated (1)."
},
{
"date": "2026-03-31T16:38:57.479236Z",
"number": "6",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-31T17:38:52.029424Z",
"number": "7",
"summary": "Unknown change."
},
{
"date": "2026-03-31T19:55:19.517989Z",
"number": "8",
"summary": "References created (1)."
},
{
"date": "2026-04-01T08:05:59.268144Z",
"number": "9",
"summary": "Source connected.| CVE status created. (valid)| Description created for source.| Products created (1)."
},
{
"date": "2026-04-01T08:06:02.361031Z",
"number": "10",
"summary": "NCSC Score updated."
},
{
"date": "2026-04-01T15:13:01.128670Z",
"number": "11",
"summary": "Source connected.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-04-01T15:13:04.509377Z",
"number": "12",
"summary": "NCSC Score updated."
},
{
"date": "2026-04-03T15:25:19.923678Z",
"number": "13",
"summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
},
{
"date": "2026-04-03T15:25:23.111894Z",
"number": "14",
"summary": "NCSC Score updated."
}
],
"status": "interim",
"version": "14"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/<=0.6.2",
"product": {
"name": "vers:unknown/<=0.6.2",
"product_id": "CSAFPID-5992138",
"product_identification_helper": {
"cpe": "cpe:2.3:a:django:slippers:*:*:*:*:*:*:*:*"
}
}
}
],
"category": "product_name",
"name": "slippers"
}
],
"category": "vendor",
"name": "django"
},
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/<0.6.3",
"product": {
"name": "vers:unknown/<0.6.3",
"product_id": "CSAFPID-5969071"
}
}
],
"category": "product_name",
"name": "slippers"
}
],
"category": "vendor",
"name": "mixxorz"
},
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/<0.6.3",
"product": {
"name": "vers:unknown/<0.6.3",
"product_id": "CSAFPID-5971088"
}
}
],
"category": "product_name",
"name": "slippers"
}
],
"category": "vendor",
"name": "unknown"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2026-34231",
"cwe": {
"id": "CWE-79",
"name": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
},
"notes": [
{
"category": "description",
"text": "## Summary\n\nA Cross-site Scripting (XSS) vulnerability exists in the `{% attrs %}` template tag of the `slippers` Django package. When a context variable containing untrusted data is passed to `{% attrs %}`, the value is interpolated into an HTML attribute string without escaping, allowing an attacker to break out of the attribute context and inject arbitrary HTML or JavaScript into the rendered page.\n\n## Vulnerability details\n\n### Root cause\n\n`AttrsNode` is a custom `Node` subclass registered via `register.tag()`. Unlike `register.simple_tag()`, which automatically applies `conditional_escape()` when autoescape is on, custom `Node.render()` methods receive no automatic escaping and are fully responsible for sanitising their output. `attr_string()` fails to do this:\n\n```python\ndef attr_string(key: str, value: Any):\n if isinstance(value, bool):\n return key if value else \"\"\n key = key.replace(\"_\", \"-\")\n return f'{key}=\"{value}\"' # value is not escaped\n```\n\n### Attack scenario\n\nGiven a template that uses `{% attrs %}` with a user-supplied value:\n\n```django\n{% load slippers %}\n\n```\n\n```python\nrender(request, \"search.html\", {\"placeholder\": request.GET.get(\"q\", \"\")})\n```\n\nAn attacker crafting a request with `q=\" onmouseover=\"alert(document.cookie)\" x=\"` produces:\n\n```html\n\n```\n\n## Impact\n\nAny template that passes values derived from user input, database content, or other untrusted sources to `{% attrs %}` is vulnerable. Successful exploitation can lead to session hijacking, credential theft, arbitrary actions on behalf of the victim, and page defacement.\n\n## Remediation\n\nReplace the f-string in `attr_string()` with `format_html()`, which escapes both key and value:\n\n```python\nfrom django.utils.html import format_html\n\ndef attr_string(key: str, value: Any):\n if isinstance(value, bool):\n return key if value else \"\"\n key = key.replace(\"_\", \"-\")\n return format_html('{}=\"{}\"', key, value)\n```\n\nUntil a patch is available, sanitise untrusted values before passing them to `{% attrs %}`, for example with `django.utils.html.escape()` in the view layer.",
"title": "github - https://api.github.com/advisories/GHSA-w7rv-gfp4-j9j3"
},
{
"category": "description",
"text": "Slippers is a UI component framework for Django. Prior to version 0.6.3, a Cross-Site Scripting (XSS) vulnerability exists in the {% attrs %} template tag of the slippers Django package. When a context variable containing untrusted data is passed to {% attrs %}, the value is interpolated into an HTML attribute string without escaping, allowing an attacker to break out of the attribute context and inject arbitrary HTML or JavaScript into the rendered page. This issue has been patched in version 0.6.3.",
"title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34231"
},
{
"category": "description",
"text": "Slippers is a UI component framework for Django. Prior to version 0.6.3, a Cross-Site Scripting (XSS) vulnerability exists in the {% attrs %} template tag of the slippers Django package. When a context variable containing untrusted data is passed to {% attrs %}, the value is interpolated into an HTML attribute string without escaping, allowing an attacker to break out of the attribute context and inject arbitrary HTML or JavaScript into the rendered page. This issue has been patched in version 0.6.3.",
"title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34231.json"
},
{
"category": "description",
"text": "Affected versions of the slippers package are vulnerable to Cross-Site Scripting (XSS) due to improper escaping of untrusted values when generating HTML attributes. The {% attrs %} template tag uses AttrsNode.render() and attr_string() to build attribute strings, but attr_string() returns f'{key}=\"{value}\"' without escaping value, so user-controlled input can break out of the attribute context.",
"title": "pyupio - https://raw.githubusercontent.com/pyupio/safety-db/refs/heads/master/data/insecure_full.json"
},
{
"category": "other",
"text": "0.00029",
"title": "EPSS"
},
{
"category": "other",
"text": "3.7",
"title": "NCSC Score"
},
{
"category": "other",
"text": "There is exploit data available from source Nvd, Is related to a product by vendor Unknown",
"title": "NCSC Score top decreasing factors"
}
],
"product_status": {
"known_affected": [
"CSAFPID-5969071",
"CSAFPID-5971088",
"CSAFPID-5992138"
]
},
"references": [
{
"category": "external",
"summary": "Source - github",
"url": "https://api.github.com/advisories/GHSA-w7rv-gfp4-j9j3"
},
{
"category": "external",
"summary": "Source - nvd",
"url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34231"
},
{
"category": "external",
"summary": "Source - cveprojectv5",
"url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34231.json"
},
{
"category": "external",
"summary": "Source - pyupio",
"url": "https://raw.githubusercontent.com/pyupio/safety-db/refs/heads/master/data/insecure_full.json"
},
{
"category": "external",
"summary": "Source - first",
"url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd",
"url": "https://github.com/mixxorz/slippers/security/advisories/GHSA-w7rv-gfp4-j9j3"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd",
"url": "https://github.com/mixxorz/slippers/commit/16cc4ef4fa8ad2f7aee30798f16c3e7b653423b2"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd",
"url": "https://github.com/mixxorz/slippers/releases/tag/0.6.3"
},
{
"category": "external",
"summary": "Reference - github",
"url": "https://github.com/advisories/GHSA-w7rv-gfp4-j9j3"
},
{
"category": "external",
"summary": "Reference - github",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34231"
}
],
"scores": [
{
"cvss_v3": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"baseScore": 6.1,
"baseSeverity": "MEDIUM"
},
"products": [
"CSAFPID-5969071",
"CSAFPID-5971088",
"CSAFPID-5992138"
]
}
],
"title": "CVE-2026-34231"
}
]
}