# [CRIT] [GHSA / CRITICAL] CVE-2026-45618: LiquidJS is Vulnerable to Remote Code Execution

**Source:** GitHub Security Advisories
**Published:** 2026-05-27
**Article:** https://github.com/advisories/GHSA-gf2q-c269-pqgc

## Threat Profile

LiquidJS is Vulnerable to Remote Code Execution

### Summary
It is possible to execute arbitrary code with crafted templates


### Details

<details>
<summary>
 `1|valueOf` -> `this` when evaluating the filter


</summary>

```liquid
{%assign r=1|valueOf%}
{{r|inspect}}
```

```json
{"context":{"scopes":[{"r":"[Circular]"}],"registers":{},"breakCalled":false,"continueCalled":false,"sync":false,"opts":{"root":["."],"layouts":["."],"partials":["."],"relativeReference":true,"jekyllInclude":false,"k…

## Indicators of Compromise (high-fidelity only)

- **CVE:** `CVE-2026-45618`

## MITRE ATT&CK Techniques

- **T1190** — Exploit Public-Facing Application
- **T1204.002** — User Execution: Malicious File
- **T1059.007** — Command and Scripting Interpreter: JavaScript
- **T1059** — Command and Scripting Interpreter
- **T1059.004** — Unix Shell

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### LiquidJS SSTI gadget tokens in inbound HTTP (CVE-2026-45618)

`UC_196_2` · phase: **exploit** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=true count min(_time) as firstTime max(_time) as lastTime values(Web.url) as url values(Web.src) as src values(Web.http_user_agent) as ua from datamodel=Web.Web where Web.url="*1%7CvalueOf*" OR Web.url="*r.context.scopes*" OR Web.url="*r.liquid.parser*" OR Web.url="*r.liquid.options.fs*" OR Web.url="*assign%20__proto__*" OR Web.url="*getBuiltinModule*" OR Web.url="*child_process*" OR Web.url="*group_by*where*first*last*" by Web.dest Web.http_method Web.status | `drop_dm_object_name("Web")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(7d)
| where ActionType in ("InboundConnectionAccepted","ConnectionInbound","ConnectionSuccess")
   or InitiatingProcessFileName in~ ("node.exe","w3wp.exe","iisexpress.exe")
| where RemoteUrl has_any ("1|valueOf","1%7CvalueOf","r.context.scopes","r.liquid.parser","r.liquid.options.fs","assign __proto__","assign%20__proto__","getBuiltinModule","child_process","execSync","fs.readFileSync")
   or AdditionalFields has_any ("1|valueOf","r.context.scopes","r.liquid.parser","__proto__","getBuiltinModule","child_process")
| project Timestamp, DeviceName, InitiatingProcessFileName, InitiatingProcessCommandLine, RemoteIP, RemoteUrl, LocalPort, AdditionalFields
| order by Timestamp desc
```

### Node.js web process spawning shell (LiquidJS RCE post-exploit)

`UC_196_3` · phase: **exploit** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=true count min(_time) as firstTime max(_time) as lastTime values(Processes.process) as process values(Processes.parent_process) as parent_process values(Processes.user) as user from datamodel=Endpoint.Processes where (Processes.parent_process_name="node.exe" OR Processes.parent_process_name="node" OR Processes.parent_process_name="w3wp.exe") (Processes.process_name="cmd.exe" OR Processes.process_name="powershell.exe" OR Processes.process_name="pwsh.exe" OR Processes.process_name="sh" OR Processes.process_name="bash" OR Processes.process_name="dash" OR Processes.process_name="zsh") by host Processes.dest Processes.process_name Processes.parent_process_name | `drop_dm_object_name("Processes")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where InitiatingProcessFileName in~ ("node.exe","node","w3wp.exe","iisnode.exe")
| where FileName in~ ("cmd.exe","powershell.exe","pwsh.exe","sh","bash","dash","zsh","ksh")
| where AccountName !endswith "$"
| project Timestamp, DeviceName, AccountName,
          ParentImage = InitiatingProcessFolderPath,
          ParentCmd   = InitiatingProcessCommandLine,
          ChildImage  = FolderPath,
          ChildCmd    = ProcessCommandLine,
          InitiatingProcessTokenElevation, ProcessIntegrityLevel, SHA256
| order by Timestamp desc
```

### Article-specific behavioural hunt — [GHSA / CRITICAL] CVE-2026-45618: LiquidJS is Vulnerable to Remote Code Executio

`UC_196_1` · phase: **install** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — [GHSA / CRITICAL] CVE-2026-45618: LiquidJS is Vulnerable to Remote Code Executio ```
| tstats `summariesonly` count
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("created","modified")
      AND (Filesystem.file_path="*/etc/passwd*")
    by Filesystem.dest, Filesystem.user, Filesystem.process_name,
       Filesystem.file_path, Filesystem.file_name
| `drop_dm_object_name(Filesystem)`
```

**Defender KQL:**
```kql
// Article-specific bespoke detection — [GHSA / CRITICAL] CVE-2026-45618: LiquidJS is Vulnerable to Remote Code Executio
// Hunts the actual binaries / paths / commandline fragments named
// in the article instead of a generic technique-class template.

// File-creation events for the named binaries / paths
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated","FileModified")
| where (FolderPath has_any ("/etc/passwd"))
| project Timestamp, DeviceName, AccountName, FolderPath,
          FileName, ActionType, InitiatingProcessFileName,
          InitiatingProcessCommandLine
| order by Timestamp desc
```

### IOC-driven hunts (use shared templates)

These are standard IOC-substitution hunts — the canonical SPL and KQL live once in [`_TEMPLATES.md`](../_TEMPLATES.md), so we don't repeat the same boilerplate on every CVE / hash / network-IOC briefing.

- **Asset exposure — vulnerability matches article CVE(s)** ([template](../_TEMPLATES.md#asset-exposure)) — phase: **recon**, confidence: **High**
  - CVE(s): `CVE-2026-45618`


## Why this matters

Severity classified as **CRIT** based on: CVE present, 4 use case(s) fired, 5 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.