CVE-2026-18756

unknown

Published 2026-08-19 · Modified 2026-08-19

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CVSS v3

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CVSS v4 NEW

7.2

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

VIR risk

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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.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-79

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.