---
cve: "CVE-2026-75583"
severity: "LOW"
cvss: 2.3
epss: "0.2%"
vendor: "ridafkih"
kev: false
exploited: false
published: "2026-08-19 16:35:53"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-22T21:51:54+02:00"
---

# CVE-2026-75583

> 2.3 LOW · 🧪 PoC

## Beschreibung

keeper.sh's calendar module version prior to 2.18.14 contains a server-side request forgery (SSRF) guard bypass vulnerability that allows authenticated attackers to reach private network addresses by exploiting a DNS rebinding attack against the two-phase URL validation and connection flow. The SSRF guard validates a hostname's resolved IP addresses but discards them before the actual HTTP connection is opened, allowing an attacker who controls authoritative DNS to return a public address during validation and a private address during the subsequent independent socket-level DNS resolution, causing the guard to pass while the outbound connection reaches internal infrastructure such as cloud instance metadata endpoints.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- aea1cf537b850509e802b388f38cf1482cb6291b (Commit)

## Referenzen

- <https://github.com/ridafkih/keeper.sh>
- <https://github.com/ridafkih/keeper.sh/security/advisories/GHSA-mxxg-qffg-j3p6>
- <https://github.com/ridafkih/keeper.sh/commit/aea1cf537b850509e802b388f38cf1482cb6291b>
- <https://www.vulncheck.com/advisories/keeper-sh-calendar-version-prior-to-ssrf-guard-bypass-via-dns-rebinding>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-75583) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_