CVE-2026-40541 (GCVE-0-2026-40541)

Vulnerability from cvelistv5 – Published: 2026-08-28 07:07 – Updated: 2026-08-28 07:07
VLAI
Summary
An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM.
Severity
9 (Critical)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version CPE status
Synology Synology Chat Server Affected: * , < 2.4.5-22148 (semver)
guessed Create a notification for this product.
Credits
Lam Jun Rong and Javier Koh, Cyber Specialists of the Digital and Intelligence Service (DIS) working with the Centre for Strategic Infocomm Technologies (CSIT) and Dr Joseph Teo, CSIT
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "Synology Chat Server",
          "vendor": "Synology",
          "versions": [
            {
              "lessThan": "2.4.5-22148",
              "status": "affected",
              "version": "*",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Lam Jun Rong and Javier Koh, Cyber Specialists of the Digital and Intelligence Service (DIS) working with the Centre for Strategic Infocomm Technologies (CSIT) and Dr Joseph Teo, CSIT"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An improper neutralization of input during web page generation (\u0027Cross-site Scripting\u0027) vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9,
            "baseSeverity": "CRITICAL",
            "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:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T07:07:24.049Z",
        "orgId": "db201096-a0cc-46c7-9a55-61d9e221bf01",
        "shortName": "synology"
      },
      "references": [
        {
          "name": "Synology-SA-26:10 Synology Chat Server",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.synology.com/en-global/security/advisory/Synology_SA_26_10"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "db201096-a0cc-46c7-9a55-61d9e221bf01",
    "assignerShortName": "synology",
    "cveId": "CVE-2026-40541",
    "datePublished": "2026-08-28T07:07:24.049Z",
    "dateReserved": "2026-04-14T01:01:14.607Z",
    "dateUpdated": "2026-08-28T07:07:24.049Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-40541\",\"sourceIdentifier\":\"security@synology.com\",\"published\":\"2026-08-28T08:16:40.713\",\"lastModified\":\"2026-08-28T08:16:40.713\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"An improper neutralization of input during web page generation (\u0027Cross-site Scripting\u0027) vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM.\"}],\"affected\":[{\"source\":\"security@synology.com\",\"affectedData\":[{\"vendor\":\"Synology\",\"product\":\"Synology Chat Server\",\"defaultStatus\":\"affected\",\"versions\":[{\"version\":\"*\",\"lessThan\":\"2.4.5-22148\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security@synology.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H\",\"baseScore\":9.0,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.3,\"impactScore\":6.0}]},\"weaknesses\":[{\"source\":\"security@synology.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"references\":[{\"url\":\"https://www.synology.com/en-global/security/advisory/Synology_SA_26_10\",\"source\":\"security@synology.com\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.

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.


Detection rules are retrieved from Rulezet.