---
cve: "CVE-2026-58657"
severity: "MEDIUM"
cvss: 4.8
epss: "0.4%"
vendor: "Grav"
kev: false
exploited: false
published: "2026-07-08 14:17:20"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T23:15:56+02:00"
---

# CVE-2026-58657

> 4.8 MEDIUM · 🧪 PoC

## Beschreibung

Grav before 2.0.0 (affected through 2.0.0-rc.9 and the 2.0 branch) contains a stored CSS injection vulnerability in the Markdown image resize() media action. Prior media hardening rejects direct ?style= payloads and unsafe attribute() fallbacks, but the resize() action in Excerpts::processMediaActions() writes caller-controlled values directly into the image's styleAttributes. A lower-privileged content editor who can edit page Markdown can store a crafted image URL with semicolon-delimited CSS declarations in the resize parameters, which are rendered into the final  attribute when a higher-privileged reviewer/admin views the page or preview. This does not require JavaScript execution but enables UI redress/overlay and content-manipulation attacks (e.g., a full-viewport fixed overlay). Fixed in 2.0.0.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Hoch | good |

## Patch verfügbar (OSV)

- bb4022f44b882ca4615188f4da5a0d646cef02ce (Commit)

## Referenzen

- <https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9>
- <https://github.com/getgrav/grav/commit/6582166173bb8eb5869d96aea384e0e73777c94c>
- <https://github.com/getgrav/grav/commit/e03d29aa0d3ece16d73c1ffccfa78df8bf5f28b8>
- <https://www.vulncheck.com/advisories/grav-stored-css-injection-via-markdown-image-resize-action>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-58657) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_