CVE-2026-105219
Mammoth.js 1.3.0 before 1.12.3 ReDoS via Style Map Tokeniser
mwilliamson mammoth.js
CVSS
8.7HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 1.12.3mammoth.jsCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
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.
Text from CVE List
Affected versions 1
- mammoth.jsaffected: 1.3.0 before 1.12.3CVE List
References 5
- github.com/mwilliamson/mammoth.js/commit/dc49225425c2c07de0a6dc3529f2386c82a032b4Fixvia CVE List
- vulncheck.com/advisories/mammoth-js-1.3.0-before-1.12.3-redos-via-style-map-tokeniserAdvisoryvia CVE List
- github.com/mwilliamson/mammoth.js/issues/487Referencevia CVE List
- github.com/mwilliamson/mammoth.js/blob/1.12.2/lib/styles/parser/tokeniser.js#L6-L30Referencevia CVE List
- github.com/mwilliamson/mammoth.jsReferencevia CVE List