---
id: CVE-2026-110802
title: >-
  Altair: DOM-based XSS via attacker-controlled script URLs in the iframe
  sandbox
summary: >-
  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() i…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
  - CWE-829
vendor: altair-graphql
product: altair
affected:
  - 'altair >= 7.2.4, < 8.5.8'
  - 'altair-express-middleware >= 7.2.4, < 8.5.8'
  - 'altair-fastify-plugin >= 7.2.4, < 8.5.8'
  - 'altair-koa-middleware >= 7.2.4, < 8.5.8'
  - 'altair-static >= 7.2.4, < 8.5.8'
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:41:52.499Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-110802'
references:
  - url: >-
      https://github.com/altair-graphql/altair/security/advisories/GHSA-752m-7p75-49gf
    label: >-
      https://github.com/altair-graphql/altair/security/advisories/GHSA-752m-7p75-49gf
  - url: >-
      https://github.com/altair-graphql/altair/commit/53a19183ce11ca147bb990c355e14ecb1dd7cd3e
    label: >-
      https://github.com/altair-graphql/altair/commit/53a19183ce11ca147bb990c355e14ecb1dd7cd3e
  - url: >-
      https://github.com/altair-graphql/altair/commit/bdf422bdaaaf3186170ba7f22e22c259072133d9
    label: >-
      https://github.com/altair-graphql/altair/commit/bdf422bdaaaf3186170ba7f22e22c259072133d9
  - url: 'https://github.com/altair-graphql/altair/releases/tag/v8.5.8'
    label: 'https://github.com/altair-graphql/altair/releases/tag/v8.5.8'
tags:
  - cve.org
ingestedAt: '2026-11-05T22:38:31.863Z'
---

## Overview

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.

## Affected

- `altair >= 7.2.4, < 8.5.8`
- `altair-express-middleware >= 7.2.4, < 8.5.8`
- `altair-fastify-plugin >= 7.2.4, < 8.5.8`
- `altair-koa-middleware >= 7.2.4, < 8.5.8`
- `altair-static >= 7.2.4, < 8.5.8`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.