CVE-2026-112183 MISP CSS Injection via Remote Tag Colour in Event Preview
Attackers can inject CSS via remote tags in MISP event previews, enabling UI spoofing or data leakage when users view linked events.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-112183?
CVE-2026-112183 is a medium-severity cross-site scripting vulnerability in MISP, published on 19 Oct 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-74
Which versions are affected by CVE-2026-112183?
How do I fix CVE-2026-112183?
No fix has been published for CVE-2026-112183 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-112183 being exploited?
There is no known exploitation of CVE-2026-112183 in the wild and no public exploit code.
Sources
Also known as GHSA-jj77-qm54-jjwq.