Vulnerability-Lookup

CVE-2026-12939 (GCVE-0-2026-12939)

Vulnerability from cvelistv5 – Published: 2026-07-29 01:29 – Updated: 2026-07-29 15:06

Title

Newsletters <= 4.15 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'link' Shortcode Attribute

Summary

The Newsletters Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'link' attribute of the post_thumbnail (and newsletters_post_thumbnail) shortcodes in versions up to and including 4.15. This is due to insufficient input sanitization and output escaping in the post_thumbnail() method in helpers/shortcode.php, which concatenates the user-controlled $link shortcode attribute directly into an href attribute without esc_url() or esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Severity

6.4 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

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

Assigner

Wordfence

References

6 references

URL	Tags
https://www.wordfence.com/threat-intel/vulnerabil…
https://plugins.trac.wordpress.org/browser/newsle…
https://plugins.trac.wordpress.org/browser/newsle…
https://plugins.trac.wordpress.org/browser/newsle…
https://plugins.trac.wordpress.org/browser/newsle…
https://plugins.trac.wordpress.org/changeset?repo…

Impacted products

1 product

Vendor	Product	Version
contrid	Newsletters	Affected: 0 , ≤ 4.15 (semver)

Credits

Wordfence PRISM

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-12939",
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                  },
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                  }
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}

GHSA-X3C9-QFW8-8R9C

Vulnerability from github – Published: 2026-07-29 03:30 – Updated: 2026-07-29 03:30

Details

Severity

6.4 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-12939"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-29T02:16:43Z",
    "severity": "MODERATE"
  },
  "details": "The Newsletters Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the \u0027link\u0027 attribute of the post_thumbnail (and newsletters_post_thumbnail) shortcodes in versions up to and including 4.15. This is due to insufficient input sanitization and output escaping in the post_thumbnail() method in helpers/shortcode.php, which concatenates the user-controlled $link shortcode attribute directly into an href attribute without esc_url() or esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.",
  "id": "GHSA-x3c9-qfw8-8r9c",
  "modified": "2026-07-29T03:30:21Z",
  "published": "2026-07-29T03:30:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12939"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L327"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L337"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/helpers/shortcode.php#L782"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/includes/checkinit.php#L182"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026old=3621582%40newsletters-lite\u0026new=3621582%40newsletters-lite"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/2ca8ab94-45b8-4705-b23b-dbc743572121?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

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.

Action not permitted

CVE-2026-12939 (GCVE-0-2026-12939)

GHSA-X3C9-QFW8-8R9C

Tags

Sightings

Nomenclature