Vulnerability-Lookup

GHSA-VFFH-47XC-PR68

Vulnerability from github – Published: 2026-10-23 15:31 – Updated: 2026-10-23 15:31

Details

A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user's signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override.

Severity

8.7 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-50053"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-642"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-23T14:17:53Z",
    "severity": "HIGH"
  },
  "details": "A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user\u0027s signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override.",
  "id": "GHSA-vffh-47xc-pr68",
  "modified": "2026-10-23T15:31:38Z",
  "published": "2026-10-23T15:31:38Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50053"
    },
    {
      "type": "WEB",
      "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"
    },
    {
      "type": "WEB",
      "url": "https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-50053 (GCVE-0-2026-50053)

Vulnerability from cvelistv5 – Published: 2026-10-23 13:15 – Updated: 2026-10-23 13:38

Title

Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL Parameters

Summary

Severity

8.7 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

CWE

CWE-642 - External Control of Critical State Data

Assigner

rapid7 CNA under the mitre root

CNA scorecard B 76/100 over 81 records in the last 180 days details

References

2 references

URL	Tags
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories	vendor-advisory
https://www.rapid7.com/blog/post/ve-breaking-zimb…	related

Impacted products

1 product

Vendor	Product	Version
Zimbra	Zimbra Collaboration Suite	Affected: 0 , ≤ 10.1.17 (semver)

Date Public

2026-10-23 12:42

Credits

Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Zimbra Collaboration Suite",
          "vendor": "Zimbra",
          "versions": [
            {
              "lessThanOrEqual": "10.1.17",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7"
        }
      ],
      "datePublic": "2026-10-23T12:42:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user\u0027s signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override."
            }
          ],
          "value": "A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user\u0027s signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "No individual metric - chain-only with CVE-2026-10632: 8.7 High"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-642",
              "description": "CWE-642 External Control of Critical State Data",
              "lang": "en",
              "type": "CWE"
            }
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      "providerMetadata": {
        "dateUpdated": "2026-10-23T13:38:40.748Z",
        "orgId": "9974b330-7714-4307-a722-5648477acda7",
        "shortName": "rapid7"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"
        },
        {
          "tags": [
            "related"
          ],
          "url": "https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL Parameters",
      "x_generator": {
        "engine": "Vulnogram 1.0.5"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "9974b330-7714-4307-a722-5648477acda7",
    "assignerShortName": "rapid7",
    "cveId": "CVE-2026-50053",
    "datePublished": "2026-10-23T13:15:44.976Z",
    "dateReserved": "2026-06-03T09:35:31.591Z",
    "dateUpdated": "2026-10-23T13:38:40.748Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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 MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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