Vulnerability-Lookup

CVE-2026-45368 (GCVE-0-2026-45368)

Vulnerability from cvelistv5 – Published: 2026-07-16 21:49 – Updated: 2026-07-18 03:18

Title

Kirby: Cross-site scripting (XSS) from links in KirbyTags and image blocks in the site frontend

Summary

Kirby is an open-source content management system. In versions prior to 4.9.1 and 5.4.1, the underlying URL methods for the KirbyTags and image blocks components did not filter out malicious URL values that resolve to script execution. The vulnerability affects four first-party Kirby renderers that produce `<a href="…">` output from editor-supplied field values: the (`link: …)` KirbyTag, the `link`: parameter of the `(image: …)` KirbyTag when it does not resolve to a known file or `self`, the `link` field of the built-in image block, and the HTML importer for the `blocks` field (which accepted the same malicious input as the image block `link` field). While simple `avascript:` URLs were already deactivated by treating them as a relative path and prepending a single slash to the URL, the use of URLs of the format `javascript://x%0A…` bypasses this protection. The `vbscript:`, `data:`, `livescript:`, `mocha:` and `jar:` schemes are affected by the same underlying gap. This issue has been fixed in versions 4.9.1 and 5.4.1.

Severity

8.4 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-18 03:18 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7994 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/getkirby/kirby/security/adviso…	x_refsource_CONFIRM
https://github.com/getkirby/kirby/releases/tag/5.4.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
getkirby	kirby	Affected: < 4.9.1 Affected: >= 5.0.0, < 5.4.1	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-45368

Vulnerability from fkie_nvd - Published: 2026-07-16 22:17 - Updated: 2026-10-24 20:10

Severity

8.4 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/getkirby/kirby/releases/tag/5.4.1
	security-advisories@github.com	https://github.com/getkirby/kirby/security/advisories/GHSA-qvjf-922g-pj44

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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    },
    {
      "lang": "es",
      "value": "Kirby es un sistema de gesti\u00f3n de contenido de c\u00f3digo abierto. En versiones anteriores a la 4.9.1 y 5.4.1, los m\u00e9todos URL subyacentes para los componentes KirbyTags y bloques de imagen no filtraban valores URL maliciosos que resultaban en la ejecuci\u00f3n de scripts. La vulnerabilidad afecta a cuatro renderizadores de Kirby de primera parte que producen una salida \u201c\u003ca href=\u201c...\u201d\u003e\u201d a partir de valores de campo proporcionados por el editor: el KirbyTag (\u201clink: ...)\u201d , el par\u00e1metro \u201clink\u201d: del KirbyTag \u201c(image: ...)\u201d cuando no se resuelve en un archivo conocido o \u201cself\u201d, el campo \u201clink\u201d del bloque de imagen incorporado, y el importador HTML para el campo \u201cblocks\u201d (que aceptaba la misma entrada maliciosa que el campo \u201clink\u201d del bloque de imagen). Aunque las URL simples \u201cjavascript_disabled: \u201d ya estaban desactivadas al tratarlas como una ruta relativa y anteponer una sola barra a la URL, el uso de URL con el formato \u201cjavascript_disabled: //x%0A...\u201d elude esta protecci\u00f3n. Los esquemas \u201cvbscript:\u201d, \u201cdata:\u201d, \u201clivescript:\u201d, \u201cmocha:\u201d y \u201cjar:\u201d se ven afectados por la misma brecha subyacente. Este problema ha sido solucionado en las versiones 4.9.1 y 5.4.1."
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          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "ACTIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45368",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-18T03:18:47.584293Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-16T22:17:02.680",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/getkirby/kirby/releases/tag/5.4.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/getkirby/kirby/security/advisories/GHSA-qvjf-922g-pj44"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-QVJF-922G-PJ44

Vulnerability from github – Published: 2026-05-27 17:42 – Updated: 2026-05-27 17:42

Summary

Kirby CMS vulnerable to cross-site scripting (XSS) from links in KirbyTags and image blocks in the site frontend

Details

TL;DR

This vulnerability affects all Kirby sites that allow the use of the (link: …) KirbyTag, the link: parameter of the (image: …) KirbyTag, the built-in image block with a link or the HTML importer for blocks, when content is authored by users who may not be fully trusted. The attack requires an authenticated Panel user with update permission to any textarea or blocks field, or write access to content files through another vector (e.g. a frontend form or content sync pipeline). Another attack vector is the use of Html::a() or Html::link() with untrusted user input.

This vulnerability is of high severity for affected sites.

Kirby sites are not affected if none of the mentioned KirbyTags or block types are used, or if every user who can edit content is fully trusted. The attack only surfaces in the site frontend (i.e. in its templates). The Panel itself is unaffected and will not execute JavaScript that was injected into the textarea or blocks field content.

Introduction

Cross-site scripting (XSS) is a type of vulnerability that allows to execute any kind of JavaScript code inside the site frontend or Panel session of the same or other users. In the Panel, a harmful script can for example trigger requests to Kirby's API with the permissions of the victim.

In a stored XSS attack, the malicious payload is saved into the content data and has the potential to affect other users or site visitors.

Such vulnerabilities are critical if a consuming application might have potential attackers in its group of authenticated Panel users. They can escalate their privileges if they get access to the Panel session of an admin user. Depending on the site, other JavaScript-powered attacks are possible.

A specific class of stored XSS exploits the javascript: URI scheme in HTML <a href> attributes. When a browser processes a click action on a link with href="javascript:…", it executes the value as JavaScript in the origin of the current page. Because the site usually runs on the same origin as the Panel API, a successful exploit in the site frontend can give the attacker full control of the victim's Panel session.

Affected components

Kirby provides four first-party renderers that produce <a href="…"> output from editor-supplied field values:

The (link: …) KirbyTag
The link: parameter of the (image: …) KirbyTag, when the parameter does not resolve to a known file or 'self'
The link field of the built-in image block
The HTML importer for the blocks field (which accepted the same malicious input as the image block link field)

Impact

In affected releases, the underlying URL methods for these components did not filter out malicious URL values that resolve to script execution. While simple javascript: URLs were already deactivated by treating them as a relative path and prepending a single slash to the URL, the use of URLs of the format javascript://x%0A… bypasses this protection. The vbscript:, data:, livescript:, mocha: and jar: schemes are affected by the same underlying gap.

The vulnerability allows attackers to inject malicious links into content. The malicious links would then be rendered on the site frontend. If a site visitor or logged in user browsing the site would click such a link, the malicious script code would then be executed in the browser.

Patches

The problem has been patched in Kirby 4.9.1 and Kirby 5.4.1. Please update to one of these or a later version to fix the vulnerability.

In all of the mentioned releases, a new Url::hasDangerousScheme() method detects URI schemes that must never appear in a rendered href or src attribute (javascript:, vbscript:, livescript:, mocha:, jar:, data:).

Url::isAbsolute() now returns false for any URL that hasDangerousScheme() identifies as dangerous, so the URL component no longer passes these values through makeAbsolute() unchanged.

Html::link() now replaces the href with an empty string when a dangerous scheme is detected, so the rendered <a> tag links back to the current page rather than executing the injected script.

The HTML importer for blocks strips link targets with a dangerous scheme.

Due to the hardening in these underlying URL methods, the affected KirbyTags and block no longer allow dangerous schemes in link targets.

Credits

Kirby thanks @offset for responsibly reporting the identified issue.

Severity

8.4 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Show details on source website

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.9.0"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "getkirby/cms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.9.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 5.4.0"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "getkirby/cms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45368"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-27T17:42:03Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### TL;DR\n\nThis vulnerability affects all Kirby sites that allow the use of the `(link: \u2026)` KirbyTag, the `link:` parameter of the `(image: \u2026)` KirbyTag, the built-in `image` block with a link or the HTML importer for blocks, when content is authored by users who may not be fully trusted. The attack requires an authenticated Panel user with update permission to any `textarea` or `blocks` field, or write access to content files through another vector (e.g. a frontend form or content sync pipeline). Another attack vector is the use of `Html::a()` or `Html::link()` with untrusted user input.\n\n**This vulnerability is of high severity for affected sites.**\n\nKirby sites are *not* affected if none of the mentioned KirbyTags or block types are used, or if every user who can edit content is fully trusted. The attack only surfaces in the site frontend (i.e. in its templates). The Panel itself is unaffected and will not execute JavaScript that was injected into the `textarea` or `blocks` field content.\n\n---\n\n### Introduction\n\nCross-site scripting (XSS) is a type of vulnerability that allows to execute any kind of JavaScript code inside the site frontend or Panel session of the same or other users. In the Panel, a harmful script can for example trigger requests to Kirby\u0027s API with the permissions of the victim.\n\nIn a *stored* XSS attack, the malicious payload is saved into the content data and has the potential to affect other users or site visitors.\n\nSuch vulnerabilities are critical if a consuming application might have potential attackers in its group of authenticated Panel users. They can escalate their privileges if they get access to the Panel session of an admin user. Depending on the site, other JavaScript-powered attacks are possible.\n\nA specific class of stored XSS exploits the `javascript:` URI scheme in HTML `\u003ca href\u003e` attributes. When a browser processes a click action on a link with `href=\"javascript:\u2026\"`, it executes the value as JavaScript in the origin of the current page. Because the site usually runs on the same origin as the Panel API, a successful exploit in the site frontend can give the attacker full control of the victim\u0027s Panel session.\n\n### Affected components\n\nKirby provides four first-party renderers that produce `\u003ca href=\"\u2026\"\u003e` output from editor-supplied field values:\n\n1. The `(link: \u2026)` KirbyTag\n2. The `link:` parameter of the `(image: \u2026)` KirbyTag, when the parameter does not resolve to a known file or `\u0027self\u0027`\n3. The link field of the built-in `image` block\n4. The HTML importer for the blocks field (which accepted the same malicious input as the `image` block link field)\n\n### Impact\n\nIn affected releases, the underlying URL methods for these components did not filter out malicious URL values that resolve to script execution. While simple `javascript:` URLs were already deactivated by treating them as a relative path and prepending a single slash to the URL, the use of URLs of the format `javascript://x%0A\u2026` bypasses this protection. The `vbscript:`, `data:`, `livescript:`, `mocha:` and `jar:` schemes are affected by the same underlying gap.\n\nThe vulnerability allows attackers to inject malicious links into content. The malicious links would then be rendered on the site frontend. If a site visitor or logged in user browsing the site would click such a link, the malicious script code would then be executed in the browser.\n\n### Patches\n\nThe problem has been patched in [Kirby 4.9.1](https://github.com/getkirby/kirby/releases/tag/4.9.1) and [Kirby 5.4.1](https://github.com/getkirby/kirby/releases/tag/5.4.1). Please update to one of these or a [later version](https://github.com/getkirby/kirby/releases) to fix the vulnerability.\n\nIn all of the mentioned releases, a new `Url::hasDangerousScheme()` method detects URI schemes that must never appear in a rendered `href` or `src` attribute (`javascript:`, `vbscript:`, `livescript:`, `mocha:`, `jar:`, `data:`).\n\n`Url::isAbsolute()` now returns `false` for any URL that `hasDangerousScheme()` identifies as dangerous, so the URL component no longer passes these values through `makeAbsolute()` unchanged.\n\n`Html::link()` now replaces the `href` with an empty string when a dangerous scheme is detected, so the rendered `\u003ca\u003e` tag links back to the current page rather than executing the injected script.\n\nThe HTML importer for blocks strips link targets with a dangerous scheme.\n\nDue to the hardening in these underlying URL methods, the affected KirbyTags and block no longer allow dangerous schemes in link targets.\n\n### Credits\n\nKirby thanks @offset for responsibly reporting the identified issue.",
  "id": "GHSA-qvjf-922g-pj44",
  "modified": "2026-05-27T17:42:03Z",
  "published": "2026-05-27T17:42:03Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/getkirby/kirby/security/advisories/GHSA-qvjf-922g-pj44"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/getkirby/kirby"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getkirby/kirby/releases/tag/4.9.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getkirby/kirby/releases/tag/5.4.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Kirby CMS vulnerable to cross-site scripting (XSS) from links in KirbyTags and image blocks in the site frontend"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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CVE-2026-45368 (GCVE-0-2026-45368)

FKIE_CVE-2026-45368

GHSA-QVJF-922G-PJ44

TL;DR

Introduction

Affected components

Impact

Patches

Credits

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour