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Medium

Indico affected by Cross-Site-Scripting via material uploads

Type: advisorySources: OSV

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerable to cross-site scripting when uploading certain file types as materials. Users should upgrade to version 3.3.10 to receive a patch. To apply the fix itself updating is sufficient, but to benefit from the strict Content Security Policy (CSP) Indico now applies by default for file downloads, update the webserver config in case one uses nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect`. For further directions, consult the GitHub Security advisory or Indico setup documentation. Some workarounds are available. Use the webserver config to apply a strict CSP for material download endpoints, and/or only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-25739
Confirmed fixed CVEs
Not specified
Updated in this feed
7 Nov 2026, 03:57 UTC · Revision 1

Source evidence

Indico affected by Cross-Site-Scripting via material uploads

core-osv · Original source

Published 19 Feb 2026, 15:39 UTC

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerable to cross-site scripting when uploading certain file types as materials. Users should upgrade to version 3.3.10 to receive a patch. To apply the fix itself updating is sufficient, but to benefit from the strict Content Security Policy (CSP) Indico now applies by default for file downloads, update the webserver config in case one uses nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect`. For further directions, consult the GitHub Security advisory or Indico setup documentation. Some workarounds are available. Use the webserver config to apply a strict CSP for material download endpoints, and/or only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico.

osv:CVE-2026-25739
Complete source record
{
  "id": "40adc4619aed5acc38866aa5286aa13c99fc7b137f2811c01645bbd5da3fb88e",
  "url": "https://osv.dev/vulnerability/CVE-2026-25739",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Indico affected by Cross-Site-Scripting via material uploads",
    "summary": "Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerable to cross-site scripting when uploading certain file types as materials. Users should upgrade to version 3.3.10 to receive a patch. To apply the fix itself updating is sufficient, but to benefit from the strict Content Security Policy (CSP) Indico now applies by default for file downloads, update the webserver config in case one uses nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect`. For further directions, consult the GitHub Security advisory or Indico setup documentation. Some workarounds are available. Use the webserver config to apply a strict CSP for material download endpoints, and/or only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico.",
    "evidence": "osv:CVE-2026-25739",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-25739",
      "aliases": [
        "CVE-2026-25739",
        "GHSA-jxc4-54g3-j7vp",
        "PYSEC-2026-2182"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/indico/indico",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "f52d44bedcec27be6ba29d7940ffefe66d68d7ee"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.3.10"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "f52d44bedcec27be6ba29d7940ffefe66d68d7ee"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.3.10"
                  },
                  {
                    "cpe": "cpe:2.3:a:cern:indico:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.3.10"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.3.9",
            "v3.3.8",
            "v3.3.7",
            "v3.3.6",
            "v3.3.5",
            "v3.3.4",
            "v3.3.3",
            "v3.3.2",
            "v3.3.1",
            "v3.3",
            "v3.2.6+docs",
            "v3.2.6",
            "v3.2.5",
            "v3.2.4",
            "v3.2.3",
            "v3.2.2",
            "v3.2.1",
            "v3.2",
            "v3.0",
            "v3.0rc2",
            "v3.0rc1",
            "v2.3.1",
            "v2.3",
            "v2.2",
            "v2.1",
            "v2.1rc6",
            "v2.1rc5",
            "v2.1rc4",
            "v2.1rc3",
            "v2.1rc2",
            "v2.1rc1",
            "v2.1b1",
            "v2.1a3",
            "v2.1a2",
            "v2.1a1",
            "v2.0rc1",
            "v2.0a1",
            "v1.9.11.dev9",
            "v1.9.11.dev8",
            "v1.9.11.dev7",
            "v1.9.11.dev6",
            "v1.9.11.dev3",
            "v1.9.9",
            "v0.97b2",
            "v0.97b"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25739.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.604152709Z",
      "provider": "osv",
      "references": [
        "https://github.com/indico/indico/releases/tag/v3.3.10",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25739.json",
        "https://github.com/indico/indico/security/advisories/GHSA-jxc4-54g3-j7vp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-25739"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25739.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-25739",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517937,
  "published_at": "2026-02-19T15:39:32.554+00:00"
}