Vulnerability in Scriban (CVE-2026-74787)
Summary
Vulnerability in Scriban (CVE-2026-74787). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
Summary
The object.to_json 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.to_json 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:
static void WriteValue(TemplateContext context, Utf8JsonWriter writer, object value)
{
var type = value?.GetType() ?? typeof(object);
if (value is null || value is string || value is bool ||
type.IsPrimitiveOrDecimal() || value is IFormattable)
{
JsonSerializer.Serialize(writer, value, type);
}
else if (value is IList || type.IsArray) {
writer.WriteStartArray();
foreach (var x in context.ToList(context.CurrentSpan, value))
{
WriteValue(context, writer, x); // recursive, no depth check
}
writer.WriteEndArray();
}
else {
writer.WriteStartObject();
var accessor = context.GetMemberAccessor(value);
foreach (var member in accessor.GetMembers(context, context.CurrentSpan, value))
{
if (…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-74787 has been found in Scriban.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Scriban CVE-2026-74787" on the vendor's site.
CVE-2026-74787 (Scriban) — CWE-674 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-674) exists in Scriban.
Check the vendor advisory for the affected versions of Scriban.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Scriban' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Scriban' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Scribanを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web disclosure@vulncheck.com
- web nvd.nist.gov
- web github.com