Nuclio: Unsanitized cron trigger event headers/body injected into CronJob shell command leads to persistent RCE (CVE-2026-52831) | HOL Guard CVE

Critical · CVSS 8.0CVE-2026-52831GHSA-V5PX-423J-PF7P

Nuclio: Unsanitized cron trigger event headers/body injected into CronJob shell command leads to persistent RCE

Answer in brief

CVE-2026-52831 records a Critical severity (CVSS 8.0) vulnerability in Nuclio: Unsanitized cron trigger event headers/body injected into CronJob shell command leads to persistent RCE. The current sources do not mark it as known exploited. The current feed maps nuclio/nuclio (generic), github.com/nuclio/nuclio (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 2, 2026Updated Sep 9, 2026Source checked Sep 17, 2026First seen by HOL Jul 8, 2026Material review Sep 9, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 8.0
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps nuclio/nuclio (generic), github.com/nuclio/nuclio (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
nuclio/nucliogeneric	< 1.16.4	Not reported
github.com/nuclio/nucliogo	<0.0.0-20260601075854-3356b86a8bfa	0.0.0-20260601075854-3356b86a8bfa

Recommended response

Check inventory. Check lockfiles and deployed manifests for nuclio/nuclio, github.com/nuclio/nuclio.
Review the reported fix. Update github.com/nuclio/nuclio to 0.0.0-20260601075854-3356b86a8bfa if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 8, 2026

Sources and claim methodology

Upstream source description

Nuclio is a "Serverless" framework for Real-Time Events and Data Processing. Prior to version 1.16.4, the Nuclio controller builds a curl invocation string for each cron trigger and stores it as the args of a Kubernetes CronJob container (/bin/sh, -c, <command>). Two fields in the trigger specification flow into this string without adequate sanitization: event.headers keys and event.body. This issue has been patched in version 1.16.4.

Quoted source text, attributed separately from HOL analysis.