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TI-2026-84327 Aliases CVE-2026-121445GHSA-4rvh-48q4-5726

svg-sanitizer ReDoS and Fail-Open via image-set CSS Stripping

Priority HIGH 69CWE-754Published · Updated

Key facts

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

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

Summary

darylldoyle svg-sanitizer from 1.0.0 before 1.1.0 contains a regular expression denial of service vulnerability in the image-set pattern of stripRemoteCssTokens() when removeRemoteReferences is enabled. An attacker can submit SVGs with many unclosed image-set tokens to exhaust CPU, or trigger PCRE limits that make sanitize() throw a TypeError and leave content unsanitized. The weakness is classified as CWE-754 (Improper Check for Unusual or Exceptional Conditions). CVSS 4.0 base score 8.2 (HIGH).

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

darylldoyle svg-sanitizer from 1.0.0 before 1.1.0 contains a regular expression denial of service vulnerability in the image-set pattern of stripRemoteCssTokens() when removeRemoteReferences is enabled. Attackers can submit SVGs with many unclosed image-set tokens to exhaust CPU, or trigger PCRE limits causing sanitize() to throw a TypeError and leave unsanitized content.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00379 32nd percentileScored 2026-11-07
Fix Fixed svg-sanitizer (darylldoyle): 1.1.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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
darylldoylesvg-sanitizer1.0.0 to before 1.1.01.1.0Patch availableCNA
  • svg-sanitizer Vendordarylldoyle Affected 1.0.0 to before 1.1.0 Fixed in 1.1.0 Patch available CNA

Remediation

Upgrade svg-sanitizer to version 1.1.0 or later. Affected versions are 1.0.0 before 1.1.0.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

  • Fix · CNA svg-sanitizer (darylldoyle) Fixed in 1.1.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    darylldoyle svg-sanitizer 1.1.0

    4 records Highest priority Priority HIGH 1 HIGH, 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-84328 Incomplete url() filtering in svg-sanitizer allows remote URL requestsPriority MEDIUM 57
    • TI-2026-84326 Algorithmic complexity denial of service in svg-sanitizer via use referencesPriority MEDIUM 44
    • TI-2026-84329 Cross-site scripting in svg-sanitizer via animateTransform on SafariPriority LOW 23
    Show all 4 records →

Timeline

  1. 2026-11-03 Threatist record created from CVE-2026-121445
  2. 2026-11-03 Alias added: GHSA-4rvh-48q4-5726
  3. 2026-11-03 CISA SSVC decision points changed
  4. 2026-11-03 Priority changed: MEDIUM → HIGH

References

Advisory 1

  • TI-2026-81116 Quadratic CPU exhaustion in svg-sanitizer PHP tag stripping CVSS 4.0HIGH 8.7
  • TI-2026-74075 Mixed-case xlink:HrEf bypasses use nesting limit in svg-sanitizer CVSS 3.1MEDIUM 6.5
  • TI-2026-69645 Denial of service in enshrined/svg-sanitize via crafted SVG DTD CVSS 3.1MEDIUM 6.5
  • TI-2026-84328 Incomplete url() filtering in svg-sanitizer allows remote URL requests CVSS 4.0MEDIUM 5.3
  • TI-2026-81115 darylldoyle svg-sanitizer CSS Injection and Remote Reference Bypass CVSS 4.0MEDIUM 5.1
  • TI-2025-34848 svg-sanitizer By-Passing Attribute Sanitization CVSS 4.0MEDIUM 5.1
See all 11 →

Sources

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