XSS in Aliasvault
CVE-2026-26266
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.[
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001
Affected products
- Aliasvault — versions < 0.26.0
Weakness classification (CWE)
References
- github.com/aliasvault/aliasvault/security/advisories/GHSA-f65p-p65r-g53q (Patch, Mitigation, Vendor Advisory)
- github.com/aliasvault/aliasvault/commit/382e2e96fa502891638a48404f6d82dc972ab481 (Patch)
- github.com/aliasvault/aliasvault/releases/tag/0.26.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-26266?
- CVE-2026-26266 is a critical-severity vulnerability in Aliasvault, classified under Cross-site Scripting. CVSS score: 9.3/10. Published 2026-03-03.
- How severe is CVE-2026-26266?
- Critical severity. CVSS v3 base score is 9.3 out of 10.