CVE-2026-18756
HumHub Community Edition 1.18.4-pl1 - Reflected XSS in Space membership request button rendering
- State
- Published
- Severity
- 7.2 High
- Published
- Aug 19, 2026
- Updated
- Aug 21, 2026
- Reserved
- Aug 4, 2026
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
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.2 High | 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 | Fluid Attacks |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
HumHubHumHub |
|
References
- https://fluidattacks.com/es/advisories/turizothird-party-advisory
- https://github.com/humhub/humhubproduct
- https://github.com/humhub/humhub/pull/8381patch
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