High · CVSS 8.7CVE-2026-106104

Quasar Framework: Super-linear regex backtracking on User-Agent lets one request stall a Quasar SSR serverCVE-2026-106104

Answer in brief

CVE-2026-106104 records a High severity (CVSS 8.7) vulnerability in Quasar Framework: Super-linear regex backtracking on User-Agent lets one request stall a Quasar SSR server. The current sources do not mark it as known exploited. The current feed maps quasarframework/quasar (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 6, 2026Updated Oct 6, 2026Source checked Oct 6, 2026First seen by HOL Oct 6, 2026Material review Oct 6, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps quasarframework/quasar (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
quasarframework/quasargeneric	<2.23.3	2.23.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for quasarframework/quasar.
Review the reported fix. Update quasarframework/quasar to 2.23.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 6, 2026

Sources and claim methodology

Upstream source description

Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to 2.23.3, Platform.parseSSR() passed an unbounded User-Agent request header to getMatch() in ui/src/plugins/platform/Platform.js, whose browser-detection expressions combined greedy captures with repeated unbounded scans. Platform belongs to autoInstalledPlugins, so this parsing occurs before routing for every SSR request. A crafted unauthenticated request containing repeated version tokens without a terminating Safari token causes super-linear backtracking and blocks the Node.js event loop, delaying every other SSR request. SPA, PWA, Electron, Cordova, Capacitor, browser-extension, and static-site-generation targets are not affected because they do not parse an attacker-controlled request header through this path. This issue is fixed in version 2.23.3.

Quoted source text, attributed separately from HOL analysis.