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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-75583 Detail

Description

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 2.3 LOW
Vector:  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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/ridafkih/keeper.sh VulnCheck
https://github.com/ridafkih/keeper.sh/commit/aea1cf537b850509e802b388f38cf1482cb6291b VulnCheck
https://github.com/ridafkih/keeper.sh/security/advisories/GHSA-mxxg-qffg-j3p6 VulnCheck
https://www.vulncheck.com/advisories/keeper-sh-calendar-version-prior-to-ssrf-guard-bypass-via-dns-rebinding VulnCheck

Weakness Enumeration

CWE-ID CWE Name Source
CWE-918 Server-Side Request Forgery (SSRF) VulnCheck  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-75583
NVD Published Date:
08/19/2026
NVD Last Modified:
08/19/2026
Source:
VulnCheck