GQL entry mutation `siteId` bypasses schema site scope, enabling cross-site content read/write/delete (CVE-2026-79990) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-79990

GQL entry mutation `siteId` bypasses schema site scope, enabling cross-site content read/write/delete

Answer in brief

CVE-2026-79990 records a Unknown severity vulnerability in GQL entry mutation `siteId` bypasses schema site scope, enabling cross-site content read/write/delete. The current sources do not mark it as known exploited. The current feed maps craftcms/cms (generic). 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 2, 2026Source checked Sep 2, 2026First seen by HOL Sep 2, 2026Material review Sep 2, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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 craftcms/cms (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
craftcms/cmsgeneric	>=5.0.0-RC1 <5.10.11	5.10.11

Recommended response

Check inventory. Check lockfiles and deployed manifests for craftcms/cms.
Review the reported fix. Update craftcms/cms to 5.10.11 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 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 2, 2026

Sources and claim methodology

Upstream source description

Craft CMS GraphQL entry mutation resolvers (saveEntry, deleteEntry) read siteIddirectly from$argumentswithout passing throughArgumentManagerprepareArguments(), which is the function that enforces site-scope filtering via array_intersect against the GraphQL schema’s allowed sites. The query path (ElementResolverprepareElementQuery) correctly calls prepareArguments()`, so queries to unauthorized sites return empty. But mutations bypass this entirely — an attacker with a token scoped to Site A can create, modify, or delete entries in Site B by passing siteId in the mutations argument.

Quoted source text, attributed separately from HOL analysis.