# Grav: Unauthenticated denial of service via unbounded image derivative dimensions

Advisory record · `GHSA-4x9g-vw65-vvf9`

- **Identifiers:** `GHSA-4x9g-vw65-vvf9` · `CVE-2026-53653` · `PKSA-pv12-m6cp-m9cd`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-770](https://cwe.mitre.org/data/definitions/770.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 14 Aug 2026
- **Updated:** 14 Aug 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 14 Aug 2026, 19:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `getgrav/grav` (Packagist): affected `>=2.0.0-beta.1, <2.0.0-rc.8 || <1.7.53`; fixed in `2.0.0-rc.8`, `1.7.53`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.7 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0052, the 45th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 14 Aug 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-4x9g-vw65-vvf9](https://github.com/advisories/GHSA-4x9g-vw65-vvf9)
- [OSV: GHSA-4x9g-vw65-vvf9](https://osv.dev/vulnerability/GHSA-4x9g-vw65-vvf9)
- <https://github.com/getgrav/grav/security/advisories/GHSA-4x9g-vw65-vvf9>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-53653>
- <https://github.com/getgrav/grav/commit/d9f9f0369a07ae5c96cde700c7949e1237b29cf6>
- <https://github.com/getgrav/grav/commit/f4c0f42eea755cedad6f626b342c88d4cba72174>
- <https://github.com/getgrav/grav>
- <https://github.com/getgrav/grav/releases/tag/1.7.53>
- <https://github.com/getgrav/grav/releases/tag/2.0.0-rc.8>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-4x9g-vw65-vvf9>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-4x9g-vw65-vvf9/>. Everything for agents: <https://agentprime.io/llms.txt>.