CVE-2026-83615
CVE-2026-83615 — xmldom: Quadratic-memory consumption
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom versions 0.1.5 through 0.6.0, appendElement in lib/sax.js uses _copy to clone the complete currentNSMap for each nested element that declares a new namespace prefix. Keeping every ancestor map live on the parse stack creates quadratic peak namespace-map storage, so a small highly compressible XML document can exhaust the process heap before application validation. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
<1%
chance of exploitation in 30 days
CVSS base
8.7
HIGH
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 8.7 | CVSS 4.0 | HIGH | n/a | n/a | cvelistV5 |
Weakness & attack patterns
- CWE-770
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1498.001Network Denial of Service: Direct Network Flood
- T1499Endpoint Denial of Service
- T1499.003Endpoint Denial of Service: Application Exhaustion Flood
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /xmldom, /sax.js.
References
7 on the record
- github.com/xmldom/xmldom/security/advisories/GHSA-965w-775f-mr7g
x_refsource_CONFIRM
- github.com/xmldom/xmldom/pull/1071
x_refsource_MISC
- github.com/xmldom/xmldom/pull/1072
x_refsource_MISC
- github.com/xmldom/xmldom/commit/954370f58c046223faf95ba77efcbc8ce014409d
x_refsource_MISC
- github.com/xmldom/xmldom/commit/dabffe884e864eeecb1f515c716f875e1bc47ec1
x_refsource_MISC
- github.com/xmldom/xmldom/releases/tag/0.8.15
x_refsource_MISC
- github.com/xmldom/xmldom/releases/tag/0.9.12
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.