CVE-2026-75583Network attack vector

Authenticated SSRF guard bypass via DNS rebinding

Published Aug 19, 2026 · Updated Aug 19, 2026

Server-side request forgery in keeper.sh before 2.18.14 allows remote authenticated users to reach private network HTTP services via DNS rebinding. In packages/calendar/src/utils/safe-fetch.ts, the guard resolves and approves a hostname during validation but then calls fetch with the original hostname instead of pinning the validated address, so the runtime performs a second DNS lookup that attacker-controlled authoritative DNS can change to a private IP. Exposure requires BLOCK_PRIVATE_RESOLUTION=true, a hostname-based calendar source that is not allowlisted, and control of that hostname's DNS; the resulting blind-to-semi-blind SSRF can probe or reach internal services, including cloud metadata endpoints where IMDSv1 is available.

CVSS severity2.3
Low
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in keeper.sh before 2.18.14 allows remote authenticated users to reach private network HTTP services via DNS rebinding. In packages/calendar/src/utils/safe-fetch.ts, the guard resolves and approves a hostname during validation but then calls fetch with the original hostname instead of pinning the validated address, so the runtime performs a second DNS lookup that attacker-controlled authoritative DNS can change to a private IP. Exposure requires BLOCK_PRIVATE_RESOLUTION=true, a hostname-based calendar source that is not allowlisted, and control of that hostname's DNS; the resulting blind-to-semi-blind SSRF can probe or reach internal services, including cloud metadata endpoints where IMDSv1 is available.

The record

CVE
CVE-2026-75583
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
Rida F'kih
Product
Keeper.sh
Classifications
CWE-918, CWE-367, T1046, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.18.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Rida F'kih · Keeper.shversion=0 <2.18.14

Published CVSS scores

2.3VulnCheckCVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
3.5VulnCheckCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1046Network Service Discovery
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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