GHSA-87mf-gv2c-c62c
MEDIUMGHSA-87mf-gv2c-c62c is a medium-severity (CVSS 5.3) CWE-248 vulnerability in ts-deepmerge. O3 Security confirms whether GHSA-87mf-gv2c-c62c is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ts-deepmerge: Prototype Method Override leads to DoS
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
ts-deepmergenpmDescription
Versions of the package ts-deepmerge before 8.0.0 are vulnerable to Uncaught Exception due to the improper handling of built-in Object.prototype methods (such as toString, valueOf). When user-controlled input contains these keys with non-function values, the resulting merged object becomes broken — any string context operation throws a TypeError, crashing the application.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ts-deepmerge | all versions | 8.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ts-deepmerge. 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 ts-deepmerge to 8.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-87mf-gv2c-c62c 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-87mf-gv2c-c62c 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-87mf-gv2c-c62c. 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-87mf-gv2c-c62c in your dependencies?
O3 detects GHSA-87mf-gv2c-c62c across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.