Vulnerability-Lookup

GHSA-VGGM-CWH9-FM3V

Vulnerability from github – Published: 2026-09-08 15:31 – Updated: 2026-09-09 03:30

Details

XenForo before 2.3.13 contains a cross-site scripting vulnerability in the dynamic redirect handler that allows unauthenticated attackers to execute arbitrary JavaScript in the board origin by crafting a malicious javascript: URI that bypasses host validation. Attackers can embed the board hostname in the URI authority component and use percent-encoded newlines to evade server-side filters, causing authenticated users who perform a Follow action to execute attacker-supplied JavaScript in their browser.

Severity

6.1 (Medium)


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

5.1 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-73319"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-08T14:17:26Z",
    "severity": "MODERATE"
  },
  "details": "XenForo before 2.3.13 contains a cross-site scripting vulnerability in the dynamic redirect handler that allows unauthenticated attackers to execute arbitrary JavaScript in the board origin by crafting a malicious javascript: URI that bypasses host validation. Attackers can embed the board hostname in the URI authority component and use percent-encoded newlines to evade server-side filters, causing authenticated users who perform a Follow action to execute attacker-supplied JavaScript in their browser.",
  "id": "GHSA-vggm-cwh9-fm3v",
  "modified": "2026-09-09T03:30:36Z",
  "published": "2026-09-08T15:31:55Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73319"
    },
    {
      "type": "WEB",
      "url": "https://bombobombone.github.io/posts/cve-2026-73319"
    },
    {
      "type": "WEB",
      "url": "https://github.com/BomboBombone/CVE-2026-73319"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/xenforo-xss-via-dynamic-redirect-handler"
    },
    {
      "type": "WEB",
      "url": "https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856"
    },
    {
      "type": "WEB",
      "url": "https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-73319 (GCVE-0-2026-73319)

Vulnerability from cvelistv5 – Published: 2026-09-08 13:19 – Updated: 2026-09-10 13:47

Title

XenForo < 2.3.13 XSS via Dynamic Redirect Handler

Summary

Severity

5.1 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

6.1 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-10 13:47 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

VulnCheck mitre root

References

5 references

URL	Tags
https://xenforo.com/community/threads/security-fi…	vendor-advisorypatch
https://xenforo.com/community/threads/xenforo-2-3…	release-notes
https://bombobombone.github.io/posts/cve-2026-73319/	technical-description
https://github.com/BomboBombone/CVE-2026-73319	exploit
https://www.vulncheck.com/advisories/xenforo-xss-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
XenForo	XenForo	Affected: 0 , < 2.3.13 (semver)

Date Public

2026-09-07 00:00

Credits

Marco Paciaroni (BomboBombone) VulnCheck

Show details on NVD website

JSON

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        "metrics": [
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                "id": "CVE-2026-73319",
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                    "Exploitation": "poc"
                  },
                  {
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                  },
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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-10T13:47:02.889081Z",
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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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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.