---
cve: "CVE-2026-53727"
severity: "HIGH"
cvss: 8.9
epss: "37%"
vendor: "premailer"
kev: false
exploited: false
published: "2026-07-17 21:17:07"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-11T09:33:03+02:00"
---

# CVE-2026-53727

> 8.9 HIGH · 🧪 PoC

## Beschreibung

css_parser is a Ruby CSS parser. From 2.2.0 until 3.0.0, CssParser::Parser#read_remote_file in lib/css_parser/parser.rb, and therefore load_uri! and the @import-following branch of add_block!, issued HTTP and HTTPS requests against any host, port, and URI without a scheme allowlist, host or IP filtering, or protection against link-local, loopback, or RFC-1918 addresses. Location: redirects were followed recursively back into the same function, which also serviced file:// URIs, so a single attacker-controlled HTTP redirect could upgrade the bug from SSRF to arbitrary local file disclosure. Any consumer of css_parser that hands it attacker-influenced CSS together with a base_uri: option is exposed. This issue is fixed in version 3.0.0.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 7d2ddf0189cd54b54f378f59daefa10cb036e476 (Commit)
- e0a151458b2a801ae265ba420862ef8b1127b3ae (Commit)

## Referenzen

- <https://github.com/premailer/css_parser/security/advisories/GHSA-9pmc-p236-855h>
- <https://github.com/premailer/css_parser/commit/7d2ddf0189cd54b54f378f59daefa10cb036e476>
- <https://github.com/premailer/css_parser/commit/e0a151458b2a801ae265ba420862ef8b1127b3ae>
- <https://github.com/premailer/css_parser/releases/tag/v3.0.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53727) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_