MISP CSS Injection via Remote Tag Colour in Event Preview
Summary
| CVE | CVE-2026-112183 |
|---|---|
| State | PUBLISHED |
| Assigner | CIRCL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-19 10:16:46 UTC |
| Updated | 2026-10-19 18:17:03 UTC |
| Description | MISP contains a CSS injection vulnerability in the remote event preview feature. When a user previews an event from a linked MISP server, the colour value associated with each remote tag is written directly into an inline CSS style attribute without sufficient validation. Although HTML entity encoding is applied, the value is interpreted as CSS within the style attribute, allowing a malicious or compromised linked server to inject arbitrary CSS declarations. An attacker with the ability to create or modify tags on a linked MISP instance can craft a tag colour value containing CSS injection payloads. When a user on the local instance views the event preview, the injected CSS is rendered, potentially allowing UI manipulation, visual spoofing, or limited information disclosure through CSS-based techniques. Preconditions: - A linked MISP server relationship exists between the victim instance and the attacker-controlled instance. - The attacker can create or modify tags on the linked server. - A victim user views the remote event preview page. Affected: <2.5.48. |
Risk And Classification
Primary CVSS: v4.0 4.8 MEDIUM from 5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/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
Problem Types: CWE-74 | CWE-74 CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | Secondary | 4.8 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 4.8 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/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
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/MISP/MISP/commit/91323b517 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | github.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: iglocska (en)
CNA: Claude Opus 5.5 (1M context) (en)
Additional Advisory Data
Solutions
CNA: The fix introduces strict validation of the tag colour value before it is rendered into a CSS style attribute. Only values matching a valid six-digit hexadecimal colour pattern (e.g. #aabbcc) are accepted; any other value is replaced with a safe default (#ffffff). This prevents arbitrary CSS from being injected through the colour field, aligning the remote tag handling with the validation already applied to local tags.