GHSA-9rmh-mm8f-r9h6
GHSA-9rmh-mm8f-r9h6 is a security vulnerability in svelte. O3 Security confirms whether GHSA-9rmh-mm8f-r9h6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Svelte: ReDoS in `<svelte:element>` Tag Validation
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
sveltenpmDescription
An internal regex in the Svelte runtime can take exponential time to test in <svelte:element this={tag}></svelte:element>. You are only vulnerable to this if you allow tags of unconstrained length. If your application only allows a predetermined list of tags or trims their length before passing them to svelte:element, you are safe.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | svelte | ≥ 5.51.5&&< 5.55.7 | 5.55.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for svelte. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update svelte to 5.55.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9rmh-mm8f-r9h6 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-9rmh-mm8f-r9h6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-9rmh-mm8f-r9h6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9rmh-mm8f-r9h6 in your dependencies?
O3 detects GHSA-9rmh-mm8f-r9h6 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.