CVE-2026-83606
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0-beta.9 until 0.9.11, the processing-instruction production in lib/grammar.js lets the greedy S+ separator and lazy Char*? data group repeatedly repartition a long whitespace tail when the required closing ?> is absent. Both parsePI and parseProcessingInstruction apply the expression to the entire remaining source, causing quadratic backtracking during DOMParser.parseFromString() under default options and allowing a small unauthenticated XML input to stall the Node.js event loop. This issue is fixed in @xmldom/xmldom version 0.9.11.
Scoring
- Severity
- HIGH
- CVSS base score
- 8.7
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- EPSS probability
- 0.30%
- CWE
- CWE-400, CWE-1333
- Published
- 2026-09-01
- Last modified
- 2026-09-01
Affected products
- xmldom xmldom
- @xmldom xmldom
Weakness type
Related vulnerabilities
- CVE-2026-89147 — Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read
- CVE-2026-87908 — multiparty vulnerable to Denial of Service via unbounded part-header accumulation
- CVE-2026-45769 — ikev2: unbounded client transform storage can lead to resource exhaustion
- CVE-2026-45768 — Suricata ldap: unbounded responses per transaction can lead to resource exhaustion
- CVE-2026-45766 — Suricata nfs: unbounded stateful structures can lead to resource exhaustion
- CVE-2026-45765 — Suricata dnp3: unbounded reassembly can lead to resource exhaustion
- CVE-2026-45759 — Suricata http1: quadratic Content-Disposition processing can lead to denial of service
- CVE-2026-87106 — Consul vulnerable to a denial of service in the native RPC listener