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Mesop Class Pollution vulnerability leads to DoS and Jailbreak attacks

Type: advisorySources: OSV

Mesop is a Python-based UI framework that allows users to build web applications. A class pollution vulnerability in Mesop prior to version 0.14.1 allows attackers to overwrite global variables and class attributes in certain Mesop modules during runtime. This vulnerability could directly lead to a denial of service (DoS) attack against the server. Additionally, it could also result in other severe consequences given the application's implementation, such as identity confusion, where an attacker could impersonate an assistant or system role within conversations. This impersonation could potentially enable jailbreak attacks when interacting with large language models (LLMs). Just like the Javascript's prototype pollution, this vulnerability could leave a way for attackers to manipulate the intended data-flow or control-flow of the application at runtime and lead to severe consequences like remote code execution when gadgets are available. Users should upgrade to version 0.14.1 to obtain a fix for the issue.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2025-30358
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 23:45 UTC · Revision 1

Source evidence

Mesop Class Pollution vulnerability leads to DoS and Jailbreak attacks

core-osv · Original source

Published 27 Mar 2025, 14:49 UTC

Mesop is a Python-based UI framework that allows users to build web applications. A class pollution vulnerability in Mesop prior to version 0.14.1 allows attackers to overwrite global variables and class attributes in certain Mesop modules during runtime. This vulnerability could directly lead to a denial of service (DoS) attack against the server. Additionally, it could also result in other severe consequences given the application's implementation, such as identity confusion, where an attacker could impersonate an assistant or system role within conversations. This impersonation could potentially enable jailbreak attacks when interacting with large language models (LLMs). Just like the Javascript's prototype pollution, this vulnerability could leave a way for attackers to manipulate the intended data-flow or control-flow of the application at runtime and lead to severe consequences like remote code execution when gadgets are available. Users should upgrade to version 0.14.1 to obtain a fix for the issue.

osv:CVE-2025-30358
Complete source record
{
  "id": "d4236e834f88e7641bbf51b09002e8268502887ee42bfb114450c9857b9cd10b",
  "url": "https://osv.dev/vulnerability/CVE-2025-30358",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Mesop Class Pollution vulnerability leads to DoS and Jailbreak attacks",
    "summary": "Mesop is a Python-based UI framework that allows users to build web applications. A class pollution vulnerability in Mesop prior to version 0.14.1 allows attackers to overwrite global variables and class attributes in certain Mesop modules during runtime. This vulnerability could directly lead to a denial of service (DoS) attack against the server. Additionally, it could also result in other severe consequences given the application's implementation, such as identity confusion, where an attacker could impersonate an assistant or system role within conversations. This impersonation could potentially enable jailbreak attacks when interacting with large language models (LLMs). Just like the Javascript's prototype pollution, this vulnerability could leave a way for attackers to manipulate the intended data-flow or control-flow of the application at runtime and lead to severe consequences like remote code execution when gadgets are available. Users should upgrade to version 0.14.1 to obtain a fix for the issue.",
    "evidence": "osv:CVE-2025-30358",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-30358",
      "aliases": [
        "CVE-2025-30358",
        "GHSA-f3mf-hm6v-jfhh",
        "PYSEC-2026-1624"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mesop-dev/mesop",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "897bf09e0b67b352cf332b8647de182b1d7b9a34"
                },
                {
                  "fixed": "748e20d4a363d89b841d62213f5b0c6b4bed788f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
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                      {
                        "fixed": "0.14.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "748e20d4a363d89b841d62213f5b0c6b4bed788f"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
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          ],
          "versions": [
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            "v0.13.0",
            "v0.12.9",
            "v0.12.8",
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            "v0.12.4",
            "v0.12.3",
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            "v0.12.1",
            "v0.12.0",
            "v0.11.1",
            "v0.11.0",
            "v0.10.0",
            "v0.9.5",
            "v0.9.4",
            "v0.9.3",
            "v0.9.2",
            "v0.9.1",
            "v0.9.0",
            "v0.8.0",
            "v0.7.2",
            "v0.7.1",
            "v0.6.0",
            "v0.5.6",
            "v0.5.5",
            "v0.5.3",
            "v0.5",
            "v0.4.2",
            "v0.4.1",
            "v0.2",
            "v0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-30358.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.617534178Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/30xxx/CVE-2025-30358.json",
        "https://github.com/mesop-dev/mesop/security/advisories/GHSA-f3mf-hm6v-jfhh",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-30358",
        "https://github.com/mesop-dev/mesop/commit/748e20d4a363d89b841d62213f5b0c6b4bed788f"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-915"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/30xxx/CVE-2025-30358.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-30358",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490974,
  "published_at": "2025-03-27T14:49:11.592+00:00"
}