CVE-2026-88867
CRITICAL 9.3 PoC AVAILABLE ALL-YEARSWWBN AVideo, in versions up to and including commit c3edcc274c389816d434acadac07ee78eaf330c1, contains a stored cross-site scripting vulnerability. objects/categoryAddNew.json.php passes the POST parameters `name` and `iconClass` to Category::setName() and Category::setIconClass(), which store the values without sanitization (setName only truncates to 45 characters). The category name is later echoed as HTML text and iconClass is echoed into a class attribute in view/modeYoutubeBottom.php and in Gallery cards (plugin/Gallery/functions.php). When the CustomizeUser option usersCanCreateNewCategories is enabled, any authenticated user with canUpload permission (granted by default via self-registration) can create a category containing a JavaScript payload; the payload then executes in the browser of any visitor, including administrators, who views a watch page or gallery entry for a video assigned to that category, allowing actions such as authenticated requests with the victim's session. The issue was unpatched at the time of reporting.
Public exploit or PoC code exists. The barrier to attack is reduced — watch closely.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 29th percentile
Impact if exploited
9.3CVSS 4.0 · CRITICAL · CNA
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ⚠User interaction: Succeeds with passive user activity
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://github.com/WWBN/AVideo/security/advisories/GHSA-283q-fq8j-mhv8
- github-search https://github.com/search?q=%22CVE-2026-88867%22&type=repositories
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-88867/poc.jsonMachine-readable PoC index for this CVE (for automation).For defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-88867/poc.json
Weakness (CWE)
- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
All CVSS metrics
- CRITICAL 9.3 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N - HIGH 8.7 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - CRITICAL 9.3 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 8.7 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N