Kirby: File upload permissions are not checked during processing of chunk data (CVE-2026-71415) | HOL Guard CVE

High severityCVE-2026-71415GHSA-67MX-6WF2-92XP

Kirby: File upload permissions are not checked during processing of chunk data

Answer in brief

CVE-2026-71415 records a High severity vulnerability in Kirby: File upload permissions are not checked during processing of chunk data. The current sources do not mark it as known exploited. The current feed maps getkirby/cms (composer), getkirby/kirby (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 Aug 31, 2026Updated Aug 31, 2026Source checked Aug 31, 2026First seen by HOL Aug 31, 2026Material review Aug 31, 2026

Upstream Advisory

Key facts

Risk: High
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
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 getkirby/cms (composer), getkirby/kirby (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
getkirby/cmscomposer	>=5.0.0,<5.5.2	5.5.2
getkirby/kirbygeneric	>= 5.0.0, < 5.5.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for getkirby/cms, getkirby/kirby.
Review the reported fix. Update getkirby/cms to 5.5.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 31, 2026

Sources and claim methodology

Upstream source description

Kirby is an open-source content management system. From 5.0.0 until 5.5.2, Kirby's REST API chunk upload handler in src/Api/Upload.php did not run the relevant upload authorization preflight in Kirby\Api\Upload::process() before Kirby\Api\Upload::processChunk() persisted chunk data. An authenticated user with the access.panel permission enabled but with files.create, files.replace, and user/users.update permissions disabled could submit requests with an Upload-Length header and leave unfinished chunks in site/cache/.uploads for 24 hours. Repeating this process could consume attacker-controlled temporary storage, prevent other users from uploading files, or prevent site logic from storing data, although final permission checks still prevented unauthorized files from reaching the content or site/accounts directories. This issue is fixed in version 5.5.2.

Quoted source text, attributed separately from HOL analysis.