Prototype pollution leading to stored XSS
Summary
| CVE | CVE-2026-23929 |
|---|---|
| State | PUBLISHED |
| Assigner | Zabbix |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-18 13:17:21 UTC |
| Updated | 2026-08-19 04:16:58 UTC |
| Description | Prototype pollution vulnerability in searchParamsToObject() is leading to a persistent XSS in Maps. URL parameter processing was not filtering dangerous properties like __proto__, combined with jQuery's unsafe element creation that traversed the prototype chain. |
Risk And Classification
Primary CVSS: v4.0 8.5 HIGH from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/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
EPSS: 0.002960000 probability, percentile 0.221980000 (date 2026-08-19)
Problem Types: CWE-1321 | CWE-1321 CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ("Prototype Pollution")
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.5 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.5 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/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
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| support.zabbix.com/browse/ZBX-28068 | [email protected] | support.zabbix.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Zabbix wants to thank Perce, 6o_o9 and Nassim BETTACH @Shenron for submitting this report on the HackerOne bug bounty platform. (en)
Additional Advisory Data
Solutions
CNA: Update the affected components to their respective fixed versions.