CVE-2026-23866Network attack vector

Arbitrary URL processing via unvalidated rich responses

Published May 1, 2026 · Updated May 1, 2026

Improper URL validation in affected WhatsApp for iOS and Android releases allows remote authenticated users to load arbitrary media URLs. AI rich response handling for Instagram Reels accepts a sender-controlled media URL without adequately verifying its source, so the recipient device processes that URL. Sending a crafted message from a WhatsApp account is sufficient to invoke OS-controlled custom URL scheme handlers on the recipient device, with reported impact limited to confidentiality.

CVSS severity4.3
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper URL validation in affected WhatsApp for iOS and Android releases allows remote authenticated users to load arbitrary media URLs. AI rich response handling for Instagram Reels accepts a sender-controlled media URL without adequately verifying its source, so the recipient device processes that URL. Sending a crafted message from a WhatsApp account is sufficient to invoke OS-controlled custom URL scheme handlers on the recipient device, with reported impact limited to confidentiality.

The record

CVE
CVE-2026-23866
Published
May 1, 2026
Updated
May 1, 2026
Vendor
Meta Platforms, Inc.
Product
WhatsApp for Android
Classifications
CWE-940
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=2.25.8.0 <2.26.7.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Meta Platforms, Inc. · WhatsApp for Androidversion=2.25.8.0 <2.26.7.10
Meta Platforms, Inc. · WhatsApp for iOSversion=2.25.8.0 <2.26.15.72

Published CVSS scores

4.3Facebook, Inc.CVSS:3.1/AV:N/AC:L/PR:L/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.

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-940Improper Verification of Source of a Communication Channel

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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