CVE-2026-23866

Incomplete validation of AI rich response messages for Instagram Reels in WhatsApp for iOS v2.25.8.0 to v2.26.15.72 and WhatsApp for Android v2.25.8.0 to v2.26.7.10 could have allowed a user to trigger processing of media content from an arbitrary URL on another user’s device, including triggering OS-controlled custom URL scheme handlers. We have not seen evidence of exploitation in the wild.

Published: 2026-05-01 Last update: 2026-05-11 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23866 is rated Low Risk (17.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23866

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-02 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23866

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2026-23866

GitHub Security Advisory for CVE-2026-23866

GHSA-4x7f-p792-g362 · Severity: medium — Incomplete validation of AI rich response messages for Instagram Reels in WhatsApp for iOS v2.25...

Affected software / configurations for CVE-2026-23866

Vendor Product Version Raw CPE
whatsapp whatsapp >= 2.25.8.0, <= 2.26.7.10 cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:android:*:*
whatsapp whatsapp >= 2.25.8.0, <= 2.26.15.72 cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:iphone_os:*:*

References for CVE-2026-23866

cvelogic Threat Intelligence