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TI-2026-67557 Aliases CVE-2026-105219GHSA-fp33-4hh4-xjj5

Mammoth.js 1.3.0 before 1.12.3 ReDoS via Style Map Tokeniser

Priority MEDIUM 44CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-1333.

Summary

Mammoth.js 1.3.0 before 1.12.3 contains a regular expression denial of service vulnerability in the style map tokeniser in lib/styles/parser/tokeniser.js due to overlapping regex alternatives. Attackers can supply a crafted .docx with an unterminated quoted string of repeated backslash escapes in mammoth/style-map to block the Node.js event loop.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00358 29th percentileScored 2026-11-07
Fix Fixed mammoth.js (mwilliamson): 1.12.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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
mwilliamsonmammoth.js1.3.0 to before 1.12.31.12.3Patch availableCNA
  • mammoth.js Vendormwilliamson Affected 1.3.0 to before 1.12.3 Fixed in 1.12.3 Patch available CNA

Remediation

  • Fix · CNA mammoth.js (mwilliamson) Fixed in 1.12.3

Timeline

  1. 2026-10-04 Threatist record created from CVE-2026-105219
  2. 2026-10-04 Alias added: GHSA-fp33-4hh4-xjj5
  3. 2026-10-05 CISA SSVC decision points changed

References

Patch 1

Other 3

  • TI-2026-63949 Prototype pollution in mwilliamson mammoth.js CVSS 4.0HIGH 8.4

Sources

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