CVE-2026-83616
CVE-2026-83616 — xmldom: Processing Instruction Target Injection Bypasses requireWellFormed
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 version 0.6.0 and earlier, Document.createProcessingInstruction(target, data) in lib/dom.js accepts an unvalidated target, while the requireWellFormed: true serializer checks only for a colon and the reserved case-insensitive xml name on 0.9.x and performs no target check on 0.8.x. Because serialization emits <?target data?>, a target containing >, ?, whitespace, or another invalid XML-name character can break the processing-instruction boundary and inject XML structure. 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-91
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, /dom.js.
References
7 on the record
- github.com/xmldom/xmldom/security/advisories/GHSA-c7q8-3ch8-vqpv
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/1cde3e31a07c41c87cfd368d6946aa477f16b4f9
x_refsource_MISC
- github.com/xmldom/xmldom/commit/3b694872bcb5c7e3cbadba961a4be2488750ce5b
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.