Angular Server-Side Rendering (SSR): Denial of Service via Numeric URL Matrix Parameters
A denial of service (DoS) vulnerability was identified in `@angular/router` when Server-Side Rendering (SSR) is enabled on Node.js (V8). When `@angular/router` parses incoming request URLs, it extracts path segments, matrix parameters, and child outlets into plain JavaScript objects (`Record`). When matrix parameter names or outlet names are numeric strings (such as `/a;990;2522`), the V8 JavaScript engine interprets them as array-indexed properties rather than named properties. Under V8's internal property-storage heuristics, setting numeric keys on an initially empty object causes V8 to allocate a dense array backing store (`HOLEY_ELEMENTS`) sized to the maximum index rather than falling back to sparse dictionary storage. Specifically, assigning sequential or moderately large numeric keys (like `990` followed by `2522`) causes V8 to allocate a contiguous backing store of ~2,522 pointers (~20 KB to 25 KB of heap) for a single 11-byte segment. Because each segment in a URL path allocates its own independent `parameters` object, an attacker can craft URLs with repeated numeric matrix parameters to achieve an asymmetric memory amplification factor of approximately **~350x**. ### Impact Successful exploitation allows an unauthenticated remote attacker to exhaust the Node.js old-space heap with modest request volume, terminating the SSR worker with an unrecoverable `JavaScript heap out of memory` fatal error and causing a Denial of Service. * **High Amplification:** A single 11-b
GHSA-ff3f-86qr-9cv3
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-ff3f-86qr-9cv3
@angular/router
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 22.2.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
@angular/router
Source reference: /affected/1/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 21.2.24
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
@angular/router
Source reference: /affected/2/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 20.3.32
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
@angular/router
Source reference: /affected/3/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "22.0.0"
},
{
"fixed": "22.2.0"
}
]
}
],
"package": {
"name": "@angular/router",
"purl": "pkg:npm/%40angular/router",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-ff3f-86qr-9cv3/GHSA-ff3f-86qr-9cv3.json"
}
},
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "21.0.0"
},
{
"fixed": "21.2.24"
}
]
}
],
"package": {
"name": "@angular/router",
"purl": "pkg:npm/%40angular/router",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-ff3f-86qr-9cv3/GHSA-ff3f-86qr-9cv3.json"
}
},
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "20.0.0"
},
{
"fixed": "20.3.32"
}
]
}
],
"package": {
"name": "@angular/router",
"purl": "pkg:npm/%40angular/router",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-ff3f-86qr-9cv3/GHSA-ff3f-86qr-9cv3.json"
}
},
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"last_affected": "19.2.25"
}
]
}
],
"package": {
"name": "@angular/router",
"purl": "pkg:npm/%40angular/router",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-ff3f-86qr-9cv3/GHSA-ff3f-86qr-9cv3.json"
}
}
]- Related CVEs
- CVE-2026-101896
Source reference:
/aliases
Publisher severity
high
Source reference: /database_specific/severity
- Event
- #39382 · Revision 1
- Added to Heist Feed
- Publisher date