CVE-2026-110802altair-graphql altair cross-site scripting
CVE-2026-110802 is a cross-site scripting in altair-graphql altair, rated medium (6.1 on CVSS 3.1).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
Input is written into a web page without escaping, so an attacker's script runs in the browser of anyone who views it. The product loads code from a source outside its control.
How it is reached
An attacker can exploit it over the network, without an account, but someone has to act first, such as opening a file or following a link.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker act inside a signed-in user's browser session. The damage can spread past the vulnerable component into others.
Is it being exploited?
CISA's SSVC assessment notes a public proof of concept.
What to do
- Apply the update for your edition of altair-graphql altair. Fixed builds: altair: 8.5.8; altair-express-middleware: 8.5.8; altair-fastify-plugin: 8.5.8; altair-koa-middleware: 8.5.8; altair-static: 8.5.8.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
Altair is a GraphQL client for all platforms. From 7.2.4 until 8.5.8, packages/altair-iframe-sandbox/src/main.ts reads plugin_sandbox_opts from the iframe-sandbox query string and passes attacker-controlled scriptUrls to injectScript() in packages/altair-core/src/utils/inject.ts, which creates script elements in the page. The intended parent iframe flow places the page in an iframe with sandbox allow-scripts and without allow-same-origin, but direct navigation to a crafted iframe-sandbox URL omits that isolation and executes the supplied script in the origin serving Altair. Exploitation requires a victim to open the crafted URL, and the resulting script can access script-readable storage and make same-origin requests according to the deployment's authentication and cookie controls. This issue is fixed in version 8.5.8.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Web front ends and single-page apps. The flaw sits between a user's browser and the web application.
- Admin consoles served to a browser. The flaw sits between a user's browser and the web application.
- Build pipelines, dependencies and plugins. The flaw sits between third-party code and your build or runtime.
- Update channels. The flaw sits between third-party code and your build or runtime.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- People who open files and links. Mail, chat and browsers are the delivery path.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between a user's browser and the web application. An attacker who crosses it can act inside a signed-in user's browser session.
Questions to answer about your own systems
- Where does altair-graphql altair run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Patches and commits
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.