CVE-2026-25739: Indico Indico Affected By Cross-Site-Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-jxc4-54g3-j7vp
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CVSS 5.4
CWE-79
Published
Advisory Summary

CVE-2026-25739 is a MODERATE (CVSS 5.4) indico affected by cross-site-scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Indico libraries in the PyPI ecosystem. The issue involves indico affected by cross-site-scripting via material uploads. Remediation is available by upgrading affected packages to version 3.3.10.

CVE-2026-25739 at a Glance

CVE Identifier CVE-2026-25739
GHSA Identifier GHSA-jxc4-54g3-j7vp
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Indico
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-25739

To remediate this vulnerability, upgrade all affected Indico dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

indico fixed: 3.3.10 
pip install indico>=3.3.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show indico

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-25739, inspect your installed packages using pip:

pip show indico

Analyze the terminal output to locate any version of Indico in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.3.10), your application is affected.

Note: The pip show indico command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Indico, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact There is a Cross-Site-Scripting vulnerability when uploading certain file types as materials. ### Patches You should to update to [Indico 3.3.10](https://github.com/indico/indico/releases/tag/v3.3.10) as soon as possible. See [the docs](https://docs.getindico.io/en/stable/installation/upgrade/) for instructions on how to update. Please be aware that to apply the fix itself updating is sufficient, but to benefit from the strict Content-Security-Policy we now apply by default for file downloads, you need to update your webserver config in case you use nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect` and add the following line to the `.xsf/indico/` location block (you can consult the Indico setup documentation for the full configuration snippet): ```nginx add_header Content-Security-Policy $upstream_http_content_security_policy; ``` ### Workarounds - Use your webserver config to apply a strict CSP for material download endpoints. - Only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico. ### For more information If you have any questions or comments about this advisory: - Open a thread in [our forum](https://talk.getindico.io/) - Email us privately at [indico-team@cern.ch](mailto:indico-team@cern.ch)

CVE-2026-25739 Affected Indico Versions

1 component(s)
Fixed Versions:
3.3.10
Product / Package Ecosystem Affected Versions Fixed Version
indico
pypi/indico
PyPI
< 3.3.10
3.3.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/indico/indico/security/advisories/GHSA-jxc4-54g3-j7vp
NVD — CVE-2026-25739 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25739
Indico Source Repository REPOSITORY
https://github.com/indico/indico
Indico Release RELEASE
https://github.com/indico/indico/releases/tag/v3.3.10

Frequently Asked Questions

What is CVE-2026-25739?
CVE-2026-25739 is a security vulnerability in Indico involving Indico Affected by Cross-Site-Scripting via material uploads under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Indico versions are affected?
Affected versions include releases prior to 3.3.10 across affected packages: indico.
What version fixes CVE-2026-25739?
Upgrading to 3.3.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is indico affected?
Yes, indico is affected in releases prior to 3.3.10. Upgrade your dependency to 3.3.10 or later.
What is the CVSS score of CVE-2026-25739?
CVE-2026-25739 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-25739?
CVE-2026-25739 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check PyPI dependencies for CVE-2026-25739?
Run the dependency tree command: 'pip show indico'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jxc4-54g3-j7vp",
  "modified" : "2026-02-19T21:29:53Z",
  "published" : "2026-02-17T18:54:31Z",
  "aliases" : [ "CVE-2026-25739" ],
  "summary" : "Indico Affected by Cross-Site-Scripting via material uploads",
  "details" : "### Impact\nThere is a Cross-Site-Scripting vulnerability when uploading certain file types as materials.\n\n### Patches\nYou should to update to [Indico 3.3.10](https://github.com/indico/indico/releases/tag/v3.3.10) as soon as possible.\nSee [the docs](https://docs.getindico.io/en/stable/installation/upgrade/) for instructions on how to update.\n\nPlease be aware that to apply the fix itself updating is sufficient, but to benefit from the strict Content-Security-Policy we now apply by default for file downloads, you need to update your webserver config in case you use nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect` and add the following line to the `.xsf/indico/` location block (you can consult the Indico setup documentation for the full configuration snippet):\n\n```nginx\nadd_header Content-Security-Policy $upstream_http_content_security_policy;\n```\n\n### Workarounds\n- Use your webserver config to apply a strict CSP for material download endpoints.\n- Only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico.\n\n### For more information\nIf you have any questions or comments about this advisory:\n\n- Open a thread in [our forum](https://talk.getindico.io/)\n- Email us privately at [indico-team@cern.ch](mailto:indico-team@cern.ch)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "indico"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.3.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/indico/indico/security/advisories/GHSA-jxc4-54g3-j7vp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25739"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/indico/indico"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/indico/indico/releases/tag/v3.3.10"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-17T18:54:31Z",
    "nvd_published_at" : "2026-02-19T16:27:15Z"
  }
}