CVE-2026-86721Public exploitNetwork attack vector

Live broadcast hijacking via constant session cookie

Published Sep 8, 2026 · Updated Sep 8, 2026

Authorization bypass in WWBN AVideo through commit c3edcc274c allows remote attackers to hijack any user's live broadcast. session_start_preload sets the generic key cookie to the literal value value; under PHP's EGPCS merge order, that cookie overwrites the submitted key read by plugin/Live/saveLive.php, so every saved RTMP key becomes the same public constant. An AVideo site must have the Live plugin enabled and at least one stream configuration saved in the affected state; no account or user interaction is then required to replace live content or prevent its owner from publishing.

CVSS severity9.1
Critical
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in WWBN AVideo through commit c3edcc274c allows remote attackers to hijack any user's live broadcast. session_start_preload sets the generic key cookie to the literal value value; under PHP's EGPCS merge order, that cookie overwrites the submitted key read by plugin/Live/saveLive.php, so every saved RTMP key becomes the same public constant. An AVideo site must have the Live plugin enabled and at least one stream configuration saved in the affected state; no account or user interaction is then required to replace live content or prevent its owner from publishing.

The record

CVE
CVE-2026-86721
Published
Sep 8, 2026
Updated
Sep 8, 2026
Vendor
WWBN
Product
AVideo
Classifications
CWE-287, CWE-639, T1491.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 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 <=c3edcc274c389816d434acadac07ee78eaf330c1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WWBN · AVideoversion=0 <=c3edcc274c389816d434acadac07ee78eaf330c1

Published CVSS scores

9.1WWBN/AVideo GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-639Authorization Bypass Through User-Controlled Key
T1491.002External Defacement

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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