vulnerability / NVI-00014144 / Revision 1
xmldom PI grammar regex ReDoS: quadratic backtracking on unterminated processing instructions
GitHub lists this reviewed advisory for @xmldom/xmldom. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
@xmldom/xmldom
source listed>= 0.9.0-beta.9, <= 0.9.10
## Summary `@xmldom/xmldom`'s processing-instruction (PI) grammar regex exhibits quadratic-time backtracking (ReDoS) when parsing an **unterminated** processing instruction. A single small XML document containing `` forces the regular expression engine into O(n²) work, stalling the Node.js event loop. The input is parsed with `DOMParser.parseFromString` under **default options**, so it is reachable from unauthenticated, network-delivered XML (SOAP/SAML, webhooks, uploads, XML APIs). ## Details The PI production in `lib/grammar.js` compiles (flags `mu`) to: ``` ^ ^^^ S+ greedy ^^^ Char*? lazy ``` - `lib/grammar.js` line 261: https://github.com/xmldom/xmldom/blob/bb7a085dc5ba1eea3212388509b97bb4b4af32b9/lib/grammar.js#L261 In the optional tail `(?:S+(Char*?))?`, both the greedy separator `S+` and the lazy data `Char*?` match XML whitespace. When the required trailing `?>` is absent, the engine must ultimately fail — but first it tries every partition of the whitespace run between `S+` and `Char*?`, which is O(n²) in the length of the trailing
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-g53g-w8rj-fmg7 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.