FKIE_CVE-2026-21580

Vulnerability from fkie_nvd - Published: 2026-08-18 22:16 - Updated: 2026-08-18 22:16
Severity
9.3 (Critical) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Summary
This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center and Server. This Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to execute arbitrary HTML or JavaScript code on a victims browser, perform actions as a higher-privileged user, and to get into the system utilizing loopholes exposed from security best-practices being overlooked. Atlassian recommends that Confluence Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Confluence Data Center and Server 9.2: Upgrade to a release greater than or equal to 9.2.21 Confluence Data Center and Server 10.2: Upgrade to a release greater than or equal to 10.2.13 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center and Server from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Bug Bounty program.
References
security@atlassian.comhttps://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768
security@atlassian.comhttps://jira.atlassian.com/browse/CONFSERVER-104381
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Confluence Data Center",
          "vendor": "Atlassian",
          "versions": [
            {
              "status": "affected",
              "version": "10.2.0 to 10.2.11"
            },
            {
              "status": "affected",
              "version": "10.1.0 to 10.1.2"
            },
            {
              "status": "affected",
              "version": "10.0.2 to 10.0.3"
            },
            {
              "status": "affected",
              "version": "9.5.1 to 9.5.4"
            },
            {
              "status": "affected",
              "version": "9.4.0 to 9.4.1"
            },
            {
              "status": "affected",
              "version": "9.3.1 to 9.3.2"
            },
            {
              "status": "affected",
              "version": "9.2.0 to 9.2.20"
            },
            {
              "status": "affected",
              "version": "9.1.0 to 9.1.1"
            },
            {
              "status": "affected",
              "version": "9.0.3"
            },
            {
              "status": "affected",
              "version": "8.9.6 to 8.9.8"
            },
            {
              "status": "affected",
              "version": "8.5.15 to 8.5.31"
            },
            {
              "status": "affected",
              "version": "7.19.27 to 7.19.30"
            },
            {
              "status": "unaffected",
              "version": "10.2.13 to 10.2.15"
            },
            {
              "status": "unaffected",
              "version": "9.2.21 to 9.2.23"
            }
          ]
        },
        {
          "product": "Confluence Server",
          "vendor": "Atlassian",
          "versions": [
            {
              "status": "affected",
              "version": "8.5.15 to 8.5.31"
            },
            {
              "status": "affected",
              "version": "7.19.27 to 7.19.30"
            }
          ]
        }
      ],
      "source": "security@atlassian.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center and Server.\r\n\r\nThis Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to execute arbitrary HTML or JavaScript code on a victims browser, perform actions as a higher-privileged user, and to get into the system utilizing loopholes exposed from security best-practices being overlooked.\r\n\r\nAtlassian recommends that Confluence Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:\r\n Confluence Data Center and Server 9.2: Upgrade to a release greater than or equal to 9.2.21\r\n\r\n Confluence Data Center and Server 10.2: Upgrade to a release greater than or equal to 10.2.13\r\n\r\nSee the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center and Server from the download center ([https://www.atlassian.com/software/confluence/download-archives]).\r\n\r\nThis vulnerability was reported via our Bug Bounty program."
    }
  ],
  "id": "CVE-2026-21580",
  "lastModified": "2026-08-18T22:16:50.140",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "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": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security@atlassian.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-18T22:16:50.140",
  "references": [
    {
      "source": "security@atlassian.com",
      "url": "https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768"
    },
    {
      "source": "security@atlassian.com",
      "url": "https://jira.atlassian.com/browse/CONFSERVER-104381"
    }
  ],
  "sourceIdentifier": "security@atlassian.com",
  "vulnStatus": "Received"
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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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.
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  • 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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