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

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.[

Published: 2026-03-03 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-26266 is rated Moderate Risk (42.5/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.24%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-26266

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.24% +0.19%
2 2026-05-10 0.03% 0.05% +0.02%
3 2026-03-04 — 0.03% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-26266

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.3 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 5.8 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]

Weakness enumeration for CVE-2026-26266

Affected software / configurations for CVE-2026-26266

Vendor Product Version Raw CPE
aliasvault aliasvault < 0.26.0 cpe:2.3:a:aliasvault:aliasvault:*:*:*:*:*:*:*:*

References for CVE-2026-26266

cvelogic Threat Intelligence