CVE-2026-27154 (GCVE-0-2026-27154)

Vulnerability from cvelistv5 – Published: 2026-02-26 21:20 – Updated: 2026-02-26 21:20
VLAI?
Title
Discourse has XSS when editing a malicious post
Summary
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` => true; and `prioritize_username_in_ux` => false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version
discourse discourse Affected: < 2025.12.2
Affected: >= 2026.1.0-latest, < 2026.1.1
Affected: >= 2026.2.0-latest, < 2026.2.0
Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "discourse",
          "vendor": "discourse",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2025.12.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 2026.1.0-latest, \u003c 2026.1.1"
            },
            {
              "status": "affected",
              "version": "\u003e= 2026.2.0-latest, \u003c 2026.2.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` =\u003e true; and `prioritize_username_in_ux` =\u003e false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 1.3,
            "baseSeverity": "LOW",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-26T21:20:25.181Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/discourse/discourse/security/advisories/GHSA-xv43-5gcp-wgw8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/discourse/discourse/security/advisories/GHSA-xv43-5gcp-wgw8"
        }
      ],
      "source": {
        "advisory": "GHSA-xv43-5gcp-wgw8",
        "discovery": "UNKNOWN"
      },
      "title": "Discourse has XSS when editing a malicious post"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27154",
    "datePublished": "2026-02-26T21:20:25.181Z",
    "dateReserved": "2026-02-18T00:18:53.962Z",
    "dateUpdated": "2026-02-26T21:20:25.181Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-27154\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-02-26T22:20:47.730\",\"lastModified\":\"2026-02-27T14:06:37.987\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` =\u003e true; and `prioritize_username_in_ux` =\u003e false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.\"},{\"lang\":\"es\",\"value\":\"Discourse es una plataforma de discusi\u00f3n de c\u00f3digo abierto. Antes de las versiones 2025.12.2, 2026.1.1 y 2026.2.0, el nombre completo de un usuario puede ser evaluado como HTML sin procesar cuando las siguientes configuraciones est\u00e1n establecidas: \u0027display_name_on_posts\u0027 =\u0026gt; true; y \u0027prioritize_username_in_ux\u0027 =\u0026gt; false. Editar una publicaci\u00f3n de un usuario malicioso activar\u00eda un XSS. Las versiones 2025.12.2, 2026.1.1 y 2026.2.0 parchean el problema. No hay soluciones alternativas conocidas disponibles.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/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\",\"baseScore\":1.3,\"baseSeverity\":\"LOW\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"LOW\",\"subIntegrityImpact\":\"LOW\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"UNREPORTED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"references\":[{\"url\":\"https://github.com/discourse/discourse/security/advisories/GHSA-xv43-5gcp-wgw8\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

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.


Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…