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CVE-2026-18756
HumHub Community Edition 1.18.4-pl1 - Reflected XSS in Space membership request button rendering
High7.2EPSS 0.47%
- Published
- Updated
- Reserved
- Assigned by
- Fluid Attacks
Description
HumHub Community Edition 1.18.4 contains a reflected cross-site scripting vulnerability in the Space membership-request workflow. An attacker can place attacker-controlled button configuration in the options query-string parameter of space/membership/request-membership-form, lure an authenticated non-member into submitting the legitimate membership request form, and cause the server to return JavaScript containing attacker-controlled code.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| Fluid AttacksCNA (assigner) | 4.0 | High7.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N |
| NVDNVD · Deferred | 4.0 | High7.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/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 (exploitation in 30 days)
- 0.47% · top 59% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Weakness
Affected products
References (3)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-18756)Record last updated .