keeper.sh Calendar version prior to 2.18.14 SSRF Guard Bypass via DNS Rebinding (CVE-2026-75583) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-75583

keeper.sh Calendar version prior to 2.18.14 SSRF Guard Bypass via DNS Rebinding

Answer in brief

CVE-2026-75583 records a Unknown severity vulnerability in keeper.sh Calendar version prior to 2.18.14 SSRF Guard Bypass via DNS Rebinding. The current sources do not mark it as known exploited. The current feed maps ridafkih/keeper.sh (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ridafkih/keeper.sh (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ridafkih/keeper.shgeneric	>=0 <2.18.14	2.18.14

Recommended response

Check inventory. Check lockfiles and deployed manifests for ridafkih/keeper.sh.
Review the reported fix. Update ridafkih/keeper.sh to 2.18.14 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.