CVE-2021-26539

MEDIUM
Published Feb 8, 20215y ago · Modified Jun 17, 20262w ago
5.3 CVSS 3.1
Medium
Find Similar
Published Feb 8, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

Apostrophe Technologies sanitize-html before 2.3.1 does not properly handle internationalized domain name (IDN) which could allow an attacker to bypass hostname whitelist validation set by the "allowedIframeHostnames" option.

CVSS Details

Base Score
5.3
Exploitability
3.9
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Affected Products 1

VendorProductVersionRange
apostrophecmssanitize-html* <2.3.1

References 3

  • advisory.checkmarx.net https://advisory.checkmarx.net/advisory/CX-2021-4308
    ExploitThird Party Advisory
  • github.com https://github.com/apostrophecms/sanitize-html/blob/main/CHANGELOG.md#231-2021-01-22
    Release NotesThird Party Advisory
  • github.com https://github.com/apostrophecms/sanitize-html/pull/458
    PatchThird Party Advisory

Remediation

  • github.com https://github.com/apostrophecms/sanitize-html/pull/458
    PatchThird Party Advisory