FKIE_CVE-2026-55089

Vulnerability from fkie_nvd - Published: 2026-08-19 20:17 - Updated: 2026-08-19 20:17
Severity
9.9 (Critical) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
Summary
Etherpad is a real-time collaborative editor. From 2.1.0 until 3.1.0, Etherpad's src/node/handler/APIHandler.ts authorizes requests to /api/2/* in the authorization_code OAuth path by using requiredClaims with the admin claim. This check requires only that the claim exists, while src/node/security/OAuth2Provider.ts issues admin: false for configured non-admin users. A non-admin user with a valid signed token can therefore invoke administrative functions including setHTML, setText, appendText, deletePad, copyPad, movePad, restoreRevision, anonymizeAuthor, listAllPads, and listAuthorsOfPad, allowing disclosure, modification, or deletion of pads across the instance. This issue is fixed in version 3.1.0.
References
security-advisories@github.comhttps://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996
security-advisories@github.comhttps://github.com/ether/etherpad/pull/7784
security-advisories@github.comhttps://github.com/ether/etherpad/releases/tag/v3.1.0
security-advisories@github.comhttps://github.com/ether/etherpad/security/advisories/GHSA-qfmh-fph3-mw8q
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/ether/etherpad/security/advisories/GHSA-qfmh-fph3-mw8q
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "etherpad",
          "vendor": "ether",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.1.0, \u003c 3.1.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Etherpad is a real-time collaborative editor. From 2.1.0 until 3.1.0, Etherpad\u0027s src/node/handler/APIHandler.ts authorizes requests to /api/2/* in the authorization_code OAuth path by using requiredClaims with the admin claim. This check requires only that the claim exists, while src/node/security/OAuth2Provider.ts issues admin: false for configured non-admin users. A non-admin user with a valid signed token can therefore invoke administrative functions including setHTML, setText, appendText, deletePad, copyPad, movePad, restoreRevision, anonymizeAuthor, listAllPads, and listAuthorsOfPad, allowing disclosure, modification, or deletion of pads across the instance. This issue is fixed in version 3.1.0."
    }
  ],
  "id": "CVE-2026-55089",
  "lastModified": "2026-08-19T20:17:18.050",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55089",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-19T19:48:52.330922Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-19T20:17:18.050",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/ether/etherpad/pull/7784"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/ether/etherpad/releases/tag/v3.1.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/ether/etherpad/security/advisories/GHSA-qfmh-fph3-mw8q"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/ether/etherpad/security/advisories/GHSA-qfmh-fph3-mw8q"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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Sightings

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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.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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