CVE-2026-77415
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedJSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.1, crafted JSONata expressions could chain several object-integrity weaknesses to execute arbitrary code. The chain could overwrite $clone to mutate objects through evaluateTransformExpression, expose and deconstruct JSONata functions or lambdas through $merge.*, replace proc.arguments.forEach used by applyProcedure, and forge internal lambda state. These primitives allowed an attacker to reach prototype getters, prototype and constructor access, and process.getBuiltinModule with child_process, executing code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.1.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe application evaluates attacker-influenced input as code, handing them a way to run logic inside the process. Depending on the runtime this can escalate directly to remote code execution. Remediation means removing dynamic evaluation of untrusted input and replacing it with safe, data-driven alternatives.
General guidance for the code injection class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- None
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedJSONata 1.8.8+ (for 1.x users) or 2.2.1+ (for 2.x users)
- Identify the current version of JSONata in use (check package.json or node_modules)
- If using JSONata 1.x, upgrade to version 1.8.8 or later
- If using JSONata 2.x, upgrade to version 2.2.1 or later
- Run existing tests to verify functionality is not broken
- Redeploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-77415 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesCVE-2026-77415 is a JSONata vulnerability with a 9.3 CVSS score, but the severity is deployment-dependent. The exploit chain—overwriting the $clone function, exposing lambdas through $merge, replacing proc.arguments.forEach, and forging lambda state—requires an attacker who controls the expression string. If your deployment processes JSONata expressions authored by your own team against trusted internal data, the exploit surface is minimal. If JSONata runs server-side evaluating untrusted client expressions, this is catastrophic. The attack is notable because it doesn't exploit a bug—it exploits intended functionality. $clone is a legitimate deep-copy operation that becomes a write primitive when an attacker controls the expression. Lambdas are evaluation targets repurposed as introspection and state-forgery vehicles. This is the same vulnerability class as the 2017-2019 prototype pollution wave in Lodash and similar libraries: trusted mutation primitives become execution vectors under hostile input. Patch to version 1.8.8 or 2.2.1 immediately if your threat model includes untrusted expression sources. However, assess whether the fix restricts extensibility patterns your workflows depend on—some legitimate use cases may break, and developers in that position face a choice between staying vulnerable or rewiring their code. The deeper problem is visibility: JSONata embeds in pipeline tools, low-code platforms, and serverless functions—often transitively, through acquired or forgotten components. Your SBOM may not flag it. The question to carry forward isn't just 'was this patched' but 'where is JSONata running as part of a workflow definition that gets re-evaluated, and is anyone monitoring that code path?'
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-77415 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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