CVE-2026-16536Network attack vector

Unauthenticated SSRF via unvalidated calendar_id URL

Published Aug 4, 2026 · Updated Aug 4, 2026

SSRF in Bram Waasdorp's Simple Google Calendar Outlook Events Widget before 3.1.0 allows remote attackers to read internal responses. The public REST calendar-rendering path passes the calendar_id URL to a server-side fetch without validating its destination. No authentication is required; reachable internal HTTP resources can be queried, and their response content is exposed in some cases.

CVSS severity5.3
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Bram Waasdorp's Simple Google Calendar Outlook Events Widget before 3.1.0 allows remote attackers to read internal responses. The public REST calendar-rendering path passes the calendar_id URL to a server-side fetch without validating its destination. No authentication is required; reachable internal HTTP resources can be queried, and their response content is exposed in some cases.

The record

CVE
CVE-2026-16536
Published
Aug 4, 2026
Updated
Aug 4, 2026
Vendor
Bram Waasdorp
Product
Simple Google Calendar Outlook Events Widget
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 <3.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bram Waasdorp · Simple Google Calendar Outlook Events Widgetversion=0 <3.1.0

Published CVSS scores

5.3WPScanCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
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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