---
cve: "CVE-2026-114731"
severity: "MEDIUM"
cvss: 5.3
epss: ""
vendor: "Roundcube"
kev: false
exploited: false
published: "2026-10-22 03:16:38"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-24T20:33:12+02:00"
---

# CVE-2026-114731

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.

## CNA-Record (Kanon, cvelistV5)

- CNA: **mitre**
- State: PUBLISHED
- Stand: 2026-10-22 02:12:34
- CNA-CVSS: **5.3** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Gering | warn |

## Schwachstellen-Klasse

- **CWE-770** — Allocation of Resources Without Limits or Throttling
  The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

## Angriffsmuster (CAPEC)

- [CAPEC-125 — Flooding](https://capec.mitre.org/data/definitions/125.html) _(Severity: Medium)_
- [CAPEC-130 — Excessive Allocation](https://capec.mitre.org/data/definitions/130.html) _(Severity: Medium)_
- [CAPEC-147 — XML Ping of the Death](https://capec.mitre.org/data/definitions/147.html) _(Severity: Medium)_
- [CAPEC-197 — Exponential Data Expansion](https://capec.mitre.org/data/definitions/197.html) _(Severity: Medium)_
- [CAPEC-229 — Serialized Data Parameter Blowup](https://capec.mitre.org/data/definitions/229.html) _(Severity: High)_
- [CAPEC-230 — Serialized Data with Nested Payloads](https://capec.mitre.org/data/definitions/230.html) _(Severity: High)_
- [CAPEC-231 — Oversized Serialized Data Payloads](https://capec.mitre.org/data/definitions/231.html) _(Severity: High)_
- [CAPEC-469 — HTTP DoS](https://capec.mitre.org/data/definitions/469.html) _(Severity: Low)_

## ATT&CK-Techniken

- [T1498.001 — Network Denial of Service: Direct Network Flood](https://attack.mitre.org/techniques/T1498/001/)
- [T1499 — Endpoint Denial of Service](https://attack.mitre.org/techniques/T1499/)
- [T1499.003 — Endpoint Denial of Service:Application Exhaustion Flood](https://attack.mitre.org/techniques/T1499/003/)
- [T1499.002 — Endpoint Denial of Service: Service Exhaustion Flood](https://attack.mitre.org/techniques/T1499/002/)

## Patch verfügbar (OSV)

- 1dd910522e73318447ed6e20bed1efd7adeb240a (Commit)
- 26d1b077f0c910a16c44c1862fe26e15f0bb3685 (Commit)

## Referenzen

- <https://bugs.debian.org/1151279>
- <https://github.com/roundcube/roundcubemail/commit/2c9f6da692fa37cad2aaf85d5b127b583d22b264>
- <https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5>
- <https://github.com/roundcube/roundcubemail/releases/tag/1.7.5>
- <https://github.com/roundcube/roundcubemail/releases/tag/1.6.20>
- <https://github.com/roundcube/roundcubemail/commit/99a5bdd05b01f45493cc0da4c96968eac7668126>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-114731/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_