SSRF in Ridafkih Keeper.sh
CVE-2026-75583
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/ridafkih/keeper.sh (product)
- github.com/ridafkih/keeper.sh/security/advisories/GHSA-mxxg-qffg-j3p6 (vendor-advisory)
- github.com/ridafkih/keeper.sh/commit/aea1cf537b850509e802b388f38cf1482cb6291b (patch)
- www.vulncheck.com/advisories/keeper-sh-calendar-version-prior-to-ssrf-guard-byp… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-75583?
- CVE-2026-75583 is a low-severity vulnerability in Ridafkih Keeper.sh, classified under Server-Side Request Forgery (SSRF). CVSS score: 3.5/10. Published 2026-08-19.
- How severe is CVE-2026-75583?
- Low severity. CVSS v3 base score is 3.5 out of 10.