CVE-2026-16268Public exploitNetwork attack vector

Unauthenticated SSRF via unsigned SNS bounce requests

Published Aug 6, 2026 · Updated Aug 6, 2026

Server-side request forgery in Tribulant Software Newsletters before 4.16 allows remote attackers to make arbitrary server-side requests. The wpmlmethod=bounce SNS handler passes a supplied SubscribeURL to wp_remote_request without verifying the SNS signature or restricting its destination. No authentication or plugin configuration is required; the blind request reaches internal and loopback services, but its response is not returned.

CVSS severityUnavailable
Unscored
EPSS probability0.44%
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 Tribulant Software Newsletters before 4.16 allows remote attackers to make arbitrary server-side requests. The wpmlmethod=bounce SNS handler passes a supplied SubscribeURL to wp_remote_request without verifying the SNS signature or restricting its destination. No authentication or plugin configuration is required; the blind request reaches internal and loopback services, but its response is not returned.

The record

CVE
CVE-2026-16268
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
Tribulant Software
Product
Newsletters
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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 <4.16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tribulant Software · Newslettersversion=0 <4.16

Published CVSS scores

No CVSS assessment is available in this record.

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 exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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