CVE-2026-89256Public exploitNetwork attack vectorHinoki check available

Stored XSS via unencoded bookmark chapter names

Published Sep 11, 2026 · Updated Sep 11, 2026

Stored XSS in the WWBN AVideo Bookmark plugin allows remote authenticated users to execute script in public watch-page visitors' browsers. bookmarkSave.json.php stores the name parameter unchanged, and generateChaptersHTML() concatenates it into watch-page HTML without encoding. Exploitation requires an enabled Bookmark plugin and ownership of a video; every visitor to that video's page runs the payload in the AVideo origin.

CVSS severity9.3
Critical
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in the WWBN AVideo Bookmark plugin allows remote authenticated users to execute script in public watch-page visitors' browsers. bookmarkSave.json.php stores the name parameter unchanged, and generateChaptersHTML() concatenates it into watch-page HTML without encoding. Exploitation requires an enabled Bookmark plugin and ownership of a video; every visitor to that video's page runs the payload in the AVideo origin.

The record

CVE
CVE-2026-89256
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
WWBN
Product
AVideo
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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?

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  1. Affected versionversion=0 <=c3edcc274c389816d434acadac07ee78eaf330c1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

WWBN · AVideoversion=0 <=c3edcc274c389816d434acadac07ee78eaf330c1

Published CVSS scores

8.7VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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