Scriban has Uncontrolled Recursion in object.to_json Causing Unrecoverable Process Crash via StackOverflowException

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary The object.tojson builtin function in Scriban performs recursive JSON serialization via an internal WriteValue() static local function that has no depth limit, no circular reference detection, and no stack overflow guard. A Scriban template containing a self-referencing object passed to object.tojson triggers unbounded recursion, causing a StackOverflowException that terminates the hosting .NET process. This is a fatal, unrecoverable crash — StackOverflowException cannot be caught by user code in .NET. Details The vulnerable code is the WriteValue() static local function at src/Scriban/Functions/ObjectFunctions.cs:494: This function has none of the safety mechanisms present in other recursive paths: - ObjectToString() at TemplateContext.Helpers.cs:98 checks ObjectRecursionLimit (default 20) - EnterRecursive() at TemplateContext.cs:957 calls RuntimeHelpers.EnsureSufficientExecutionStack() - CheckAbort() at TemplateContext.cs:464 also calls EnsureSufficientExecutionStack() The…

Published by the source

24 Mar 2026, 22:15 UTC

Last modified by the source

6 Jul 2026, 13:09 UTC

Source last checked

26 Oct 2026, 17:05 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xcx6-vp38-8hr5

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# Patch Next advisory brief: GHSA-xcx6-vp38-8hr5

Advisory: Scriban has Uncontrolled Recursion in `object.to_json` Causing Unrecoverable Process Crash via StackOverflowException
IDs: GHSA-xcx6-vp38-8hr5
Record: https://patchnext.com/advisories/ghsa-xcx6-vp38-8hr5 (revision 1, source checked 26 Oct 2026, 17:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: scriban.signed 7.0.0; scriban 7.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet scriban.signed: affected < 7.0.0; fixed in 7.0.0
- NuGet scriban: affected < 7.0.0; fixed in 7.0.0

## Suggested inspection (read-only)
- NuGet scriban.signed: check the installed version with your package manager.
- NuGet scriban: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on scriban.signed, scriban.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xcx6-vp38-8hr5 (GitHub-reviewed advisory GHSA-xcx6-vp38-8hr5 lists affected ranges: NuGet scriban >=0 =0 <7.0.0)

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